In game the already existing La-5 sits at an awkward spot where it is overshadowed by almost all other fighters in the game. Its 4/4 stats at 4 cost are not unique to the La-5, the Typhoon has the same stats with a text that is hard to use efficiently but not impossible, and the P-40 N-5 has the same stats with an incredible ability that is almost unmatched by any other fighter in the game. The BF 109 E at 3 cost is almost an identical plane to the La-5, only losing 1 attack for its cheaper cost, and the new P-39 has the same stats as the BF 109 E combined with a very unique and versatile text at the same cost as the La-5. Within the same Soviet nation, the Yak-3 sits at the same cost with 3/5 stats on top of powerful ambush and a text that can make it very circumstantially cheaper. To sum it all up, the La-5 is quite underpowered. It’s hard to make improvements to the stats however because of some of the 5 cost fighters in the game.
The Spitfire MK I at 5 cost 5/5 stats no text seems to me to be the standard for which 5 cost fighters should be compared to. Most other fighters at the cost have 3 or 4 attack, sacrificing raw aggressive power for more defense or for texts that add versatility to the card. The RAAF Lightning for example has the same defense as the Spitfire but 2 less attack for a very powerful and versatile bounce text. Another less prominent example is the Yak 9 which has the same stats as the Lightning but draws a Soviet card on destruction. Both lose some stats to gain substantial utility, and it shows in which ones are played more often. Most British control decks will fit in RAAF Lightnings for the value they can make, while there isn’t a single deck outside of draft that wants to run the Spitfire MK I. There are less extreme examples of cards sacrificing Spitfire stats to gain utility. The Mig 3, HE 219, and P-61 Blackwidow are the best examples. All three have the same stat line of 4/5 which is 1 attack less than the Spitfire and in return they get a specific text to them. Their texts aren’t as powerful as the Lightning bounce or the Yak 9 draw effect, but they can circumstantially have a strong effect. Against burn decks the HE 219 makes the enemy suffer for each chip damage they do, against countermeasure decks(almost always discard decks) the Mig 3 becomes incredibly cheap and cost effective, and in ramp US air decks the Blackwidow can enable cheaper attacks and thus aggression on the opponent giving more kredits to work with and snowball. All 3 of these texts are far more circumstantial than the even less stated Yak 9 and lightning, but they have at least something interesting and valuable to them compared to the Spitfire. The Spitfire isn’t alone though, it gets a friend in the category of bland and focused only on raw stats in the F4U-4 Corsair which sits at an even more awkward 4/6 stats.
The Corsair acts as another guiding principle for stats at 5 cost. The closest other plane in stats to it is the P-47 which has the same defense but 1 less attack in exchange for a very cool text of drawing cards when it destroys a unit in combat. While not as consistent as the Yak 9 in card draw, it can circumstantially draw even more than the Yak could with the added benefit of 1 defense. Comparing it back to the Corsair, the P-47 is in worst circumstances only 1 attack worse than it but in most other circumstances far superior to it with text. The other most comparable 5 cost fighter is the Zero which sacrifices 2 defense for a mediocre on deploy damage but a far more substantial ambush text. While technically the Corsair beats out the Zero on a fighter to fighter basis, the Zero is far more versatile and dangerous to other units in the game, especially the other 5 cost fighters. In fact the Corsair only really gets to be as good as the other 5 cost fighters when it fights the Zero, and that's all that the Corsair can really offer.
What makes balancing cards so difficult with the Corsair and the Spitfire in their bland forms is they set a relative cap for stats which fighters at the cost can have. Making a 5/5 fighter with any text will instantly force the Spitfire into obsolescence. The Corsair already feels that obsolescence with the existence of the P-47 having so much more potential at a cost of only 1 attack. This problem exists in more than just 5 cost fighters though, it also exists in 4 cost fighters with the La-5 as explained earlier. The La-5 exists in complete obsolescence even though it fits the line of equally stated bland fighters. At 3 cost there is the French M.S.406 with 3/3, the Soviet La-5 at 4 cost with 4/4, the British Spitfire MK I at 5 cost with 5/5, and the British Spitfire MK VI at 6 cost with 6/6. These planes should serve as a relative max to what equal cost fighters should have for stats in combination with texts, but there are so many holes in that system. The La-5 and Spitfire MK I have already been explained, but it gets even worse with the M.S.406
The most egregious of obsolescent planes is the M.S.406, it was literally put into the game at an obsolescent point, not even power crept to that point like the others. The base game BF 109 E as far as I know has not changed since I joined the game over a year ago when the change to AA and tank destroyers was made. The M.S.406 was introduced in the Allegiance expansion alongside the rest of the French nation as a support nation. Its stats are 3/3 with no text and was immediately overshadowed by the BF 109 E with its 3/4 stats and no text. Considering that France can only be a support nation and there is a limit to what French cards can be played in a deck it is ridiculous that the M.S.406 could have ever been considered a playable card at all. Outside of Germany the M.S.406 is overshadowed still by other fighters of the same cost and stats such as the F4F-4 Wildcat that gives smokescreen to the HQ, the Hurricane MK II which has fury, and the Japanese fighter that ignores countermeasures. Even at 2 cost fighters the M.S.406 feels weak because of the F4F-3 which has only 1 less attack for 1 less cost and the I 16 Ishak that has 1 less defense for 1 less cost. The 3 cost French fighter has no right to exist in the game in its current state and is practically unplayable for how terrible it is compared to its peers. The only problem though is its place in the line of equally balanced fighters at each tier.
The M.S.406 and the La-5 both suffer from power creep yet they don’t deviate from the rest of the line of equally stated fighters which serve as the baseline for stats on fighters at each tier of cost. What this means is that there is an imbalance of power in this stat line. The problem is even more apparent at 1 and 2 cost fighters where the base stat lines are not that even 2/2 or 1/1 like the balancing scale would suggest. The only fighters at 1 cost are the Gladiator and the Arado. The Gladiator has 1/3 stats which surmount to 4 total, more equivalent to 2/2 than 1/1 like the line would suggest, and the Arado 196 has 1/2 stats and a specific card draw that is meant to be circumstantial but actually activates very consistently. They have good stats overall, but are definitely weakened by their lack of aggression in only 1 attack. At 2 cost there is a much larger list of fighters and an added layer of nuance to the balancing.
The 1 cost fighters only had 1 operation cost, and many of the 2 cost fighters share that same aspect. The I-15 Chaika, F6F Hellcat, HS 126, and Macchi C.202 all have one operation cost, but the C.202 is weird and doesn’t fit into the comparisons. These 3 aircraft all have the same stats as the Arado at 1 cost, more specifically 1 attack, 2 defense and a special ability to them, such as buffs or creating more units. The 2 cost fighters with 1 attack are the ones that get the low operation cost because their aggressive abilities are very minimal or slow, while the value from them comes from their unique texts. These fighters are more comparable to the RAAF Lightning and Yak 9 at 5 cost which have less stats than other fighters at the same cost but strong abilities. The other 2 cost fighters like the I-16 Ishak, F4F-3 Wildcat, and the A5M4 Claude all have more stats than the other fighters but a much higher operation cost of 2. Even though it only costs 1 more than the standard 1 cost it is a very heavy burden with the lower cost fighters where it is just as expensive to put a fighter down as it is to attack with it. In return they get stats that are proportionally far superior to their contemporaries. The difference between 1/2 and 2/3 in stats are far more substantial than 3/5 and 5/5 proportionally even if the number between them is the same. Theoretically a F4F-3 Wildcat can take out 3 other Henshels or Chikas with its stats while the Spitfire can only take down 2 Yak 9s or RAAF lightnings. That proportional difference in stats is also important in the ability to trade with even more expensive units with more stats. It takes 4 Henshels to take down a Bf 109 E while it only takes 2 F4F-3 Wildcats. The more expensive and more stated the units get the more it becomes a battle of getting that defense and attack number over the other, and the proportionality is smaller and has far less impact. At the lower costs it has a significant impact but it is balanced by the operation costs. The I-16 Ishak and F4F-3 Wildcat may have excellent costs for the stats proportionally but they pay with their high operation costs. It’s not easy to balance the low cost fighters because of operation costs and the proportionality of cards, but I think that they are in a very good position over all. The real problem is the very awkward and insignificant stat change that occurs in the transition between 2 and 3 cost fighters.
The change between the I-16 Ishak and the M.S.406 is 1 defense at 1 cost which proportionally is very little as well. And it's not as though the operation cost gets massively better either, it's the same it just doesn’t feel as expensive because it doesn’t cost as much as the plane itself. To make the transition between lower cost and medium cost fighters the stats of the baseline fighter should be changed slightly. M.S.406 for example should have either minimum same stats as BF 109 E or it should have some interesting text to compensate. La-5 should have a minimum of 1 more defense or some interesting text to it too. The Spitfire MK I even though it fits well in the rest of the 5 cost fighters should have either some text added to it or 1 more defense. The F4U-1C Corsair also needs an improvement too, although I think adding another defense to it would just be silly to make a 4/7 fighter, giving it a text seems more fitting to me. The part where things start to get awkward again is at the Spitfire MK V which is the 6 cost 6/6 which is strong enough as it is and doesn’t really need a change. It is currently the biggest fighter in the game with exception to the ME 262 and Tempest which each present their own issues. Making what is really the strongest plane in the game even stronger is pretty awkward, but it fits best with the rest of the changes. Giving it just a single point of defense or attack extra doesn’t seem strong enough to me though, because with larger units comes more efficiency in value. I think that the Spitfire MK V could get an additional attack and defense, or a defense and a light text without causing too much of an upset to balance. The only problem with this is that the rest of the 6 cost fighters range from being tech cards like F4U-1D Corsair, Mosquito and Komet, to just bad like the P-51 and Apache. The only one that is comparable is the FW 190 which is also a tech card but with good stats, and I think that the Spitfire MK V could be made more than just 1/1 stronger, it could easily be 2/2 stronger than it because of high cost efficiencies.
In short, the M.S.406, La-5, Spitfire MK I, F4U-1C Corsair, and Spitfire MK V all suck. The first two are blatantly obsolete, but the others less obviously so. These fighters all create a difficult precedent to make new fighters with due to their lack of utility at very negligent gains in overall stats. Making 4 and 5 cost fighters suffer the most as the lines of balance for the two are very small because of how awkwardly balanced the fighters are in comparison to the La-5 and Spitfire MK I. Those two fighters plus the M.S.406 especially need to be changed in order to reduce the effects of power creep and to give more freedom in making new fighters to fill the ranks.