OK, let me now defend my choices:
A6M3: This was the IJN fighter that opposed the US in the context of most early Pacific CT setups. It performs significantly better than does the A6M2, but significantly worse than does the A6M5.
B-25B: This would give an early war level bomber to the Allies that could actually be caught by the early war Axis fighters. The Boston Mk III is simply too fast. The B-25B would be most useful in Pacific setups.
B-29A: OK, this isn't really needed. It was a major part of the end-game war in the Pacific though.
Beaufighter Mk 21: This adds an earlier ground attack aircraft for the RAF, one that saw service everywhere.
Bf109G-14: This closes a big gap in the Bf109 series as represented in AH, the performance gap between the 1943 Bf109G-6 and the late 1944 performance of the Bf109G-10. The Bf109G-14 (or Bf109G-6/AS) was the main 109 that opposed the US during the big bomber operations of early-late 1944.
B6N2: Gives the Japanese an attack aircraft with a prayer of doing its job. It is a good foil for the TBM-3.
Cant Z.1007: Best Italian bomber used in significant numbers. Gives greater variety to Med. Theatre setups. An S.M.79-II would also be OK, though it isn't as good.
F6F-3: Gives the USN a 1943 version of the F6F which I understand to be lower performing than the July, 1944 F6F-5 we have. At the very least it shouldn't carry the massive bombload of the F6F-5. If I'm mistaken, discont it from the list.
Fw190A-1: Gives a 1941 Fw190A so that the period in which the 190 was first introduced can be run with only Spitfire Vs to oppose it. Looking at the Fw190A-4 it seems to me to be so similar to the Fw190A-5 that the Fw190A-5 can be subbed in for it painlessly. We need an early Fw190.
G4M2: This would give the Japanese an early war bomber that the early war Allied fighters could actually catch and kill. The Ki.67 is way too fast and well gunned for the early Allied fighters to deal with.
H8K2: This would give the Japanese a bomber with a actually useful war load. This isn't needed for historical purposes, but rather for balance purposes.
He111H-3: The He111 was the most common bomber of the Luftwaffe. We need a version at some point, but it isn't really needed as the Ju88A-4 can stand in for it. Lower priority, but I still want the He111.
He177A-5: This would give the German a bomber with a actually useful defensive armament and a chance of getting the job done. This isn't needed for historical purposes, but rather for balance purposes. The He177A-5, Do217 or Ju188A-2 all fill this role. I'd prefer the Ju188A-2, but the bonafide Luftwaffe fans seem to prefer the He177A-5.
I-16-18: This would give us a machine gun only I-16, which many of those used by Russia at the start were. It isn't really needed, but might be easy for HTC to do at the same time as the I-16-24.
I-16-24: The I-16 is an important Russian fighter for the early war period. The I-16-24 was the best version and would add greatly to the depth of the Russian planeset which is now dominated by the late war fighters.
Il-10: This would give the Russians a late war ground attack aircraft. It saw some use against the Germans at the end of the war, and substantial use against the Japanese in 1945.
J2M3: The J2M3 would add a good mid-war fighter to the Japanese arsenal, something they lack now.
Ju87D-1: The Ju87 is a classic aircraft of WWII. The D-1 version was used extensively in Russia and can sub for the BoB B-1 model painlessly.
Ju87G-1: The anti-tank version of the Ju87. Not truly needed, but much requested.
Ju88G-7b: The best fighter version of the Ju88. It would give the Germans a heavy fighter and get some more use out of the Ju88 polygons already present.
Ju188A-2: See He177A-5 text. I prefer this to the He177A-5.
Ki.43-Ic: Gives the Japanese army an early war fighter, but armed with two 12.7mm machine guns rather than the two 7.7mm guns. With the two 12.7mm guns it could actually be used.
Ki.43-IIb: Like with all war long fighters multiple versions of the Ki.43 are needed to represent its improving performance. This is a mid-war Ki.43.
Ki.43-IIIb: Like with all war long fighters multiple versions of the Ki.43 are needed to represent its improving performance. This is a late-war Ki.43.
Ki.44-IIb: This gives the Japanese army a usable mid-war interceptor.
Ki.61-Ia: This is an early version of the Ki.61. It is needed so that the 1944 Ki.61-I-KAIc doesn't get subbed into early war setups.
Ki.61-IIb: This is the improved Ki.61 and would be useful for late-war setups.
Ki.84-Ia: This is the best Japanese fighter of the war, and unlike the N1K2-J it was produced in huge numbers. It would be a huge balancing factor for Pac. Theatre setups set in 1944 or later.
Ki.100: A end war fighter, but supposedly a good one that can use much of the Ki.61's polygons.
Ki.102b: Gives the Japanese a ground attack aircraft, though only at the end. The Ki.45 might work for the early war.
LaGG-3: An early war Russian fighter using much of the La-5FN's polygons. Fills out the early war Russian set.
La-5: Not really needed, but would get rid of the need to sub in the significantly better La-5FN for some setups.
Me410B-2: OK, not needed as the Bf110G-2 does this job, but the Me410 is a neat aircraft.
MiG-3: An early war Russian fighter that is unusually fast and lightly armed. Fills out the early Russian planeset.
Mosquito NF.Mk II: The first Combatant Mossie. Allows the Mosquito to be used in earlier setups, though without the bombs. Reuses the Mossie polygons.
Mosquito B.Mk IV: The 1942 Mossie bomber. Reuses the Mossie polygons.
Mosquito B.Mk XVI: The best Mossie bomber, useful for late war setups. Reuses much of the Mossie polygons.
Mosquito FB.Mk XVIII: OK, not needed, but who doesn't want to fire a 57mm cannon? Essentially a Mossie 6 with a different gun package and internal payload. Reuses the Mossie polygons.
Mosquito NF.Mk XXX: Adds a late war Mossie fighter with the performance it should have against the likes of the Ju88G-7b. Reuses much of the Mossie polygons.
P-38G: We need an early P-38. I can never keep which is which straight. I don't care if it is an F, G or H so long as it has early war performance.
P-39D: The P-39 was a widely used fighter. The P-39Q would be good as well.
Pe-2FT: This is an early war version of the Pe-2. We need more than one Pe-2 because a late war Pe-2 would rule the early war setups the way the Ki.67 does and an early war Pe-2 would be a joke in late war setups the way the Ju88A-4 is. I used to favor the Tu-2 over the Pe-2, but after doing more research I changed my mind. the Pe-2 can be used to cover the entire war while using the same polygons whereas the Tu-2 is only late war.
Pe-2B: This is a mid-war Pe-2.
Pe-2D: This is a late-war Pe-2. It lacks the bomb load of the Tu-2, but is faster.
Spitfire LF.Mk IX: This closes a big gap in the Spitfire representation in AH. Currently we must use a 1942 Spitfire Mk IX for all setups from 1942 to the end, when in fact the Merlin 61 Spitfire was a rare player. The Spitfire Mk VIII could be used instead of the LF.Mk IX.
TBD Devastator: Ok, this is spite. If the Japanese must be saddled with the B5N in the early war, then the USN should be saddled with this turd. It is both spite and balancing.
Tupolev SB-2: This would serve as an early war crappy Russian bomber, and by doing so fill out the early Russian set.
Wellington B.Mk IX: Or any other early version. This would be useful as an early war Allied bomber that the Axis fighters could catch, yet has a usable war load. The Boston Mk III is simply too fast. This would be used in European Theatre setups.
Yak-1: This would help fill out the mid-war Russian planeset. This would use the Yak polygons.
Yak-7: This would help fill out the mid-war Russian planeset. This would use the Yak polygons.
Yak-9D: OK, I mis read on this one. It isn't needed.