The way that FMOD generates sounds for the game is different than the way it was in AH2. The way HTC approached it in AH2 was to minimize the size and number of audio files to make it economical, if you will. A few sounds that are used in many different machines makes sense when you want to make it easy on the various computers your users might use.
When HTC went to collect audio to use they came up with up to sixteen tracks (I don't know if that was interior or exterior, or both). For sure, interior sounds have almost nothing to do with exterior sounds. It's just the way sound works, so that when a man is inside of a canopy and close to the sound source that he will hear things differently than someone outside.
Listen to the 262. It is nearly perfect as is. Perhaps, it could use a little adjustment, but it's really, really good. There are other aircraft and vehicles that are probably very good, also. To make things perfect is going to take some time. I have been playing some of the aircraft and I think some like the Storch could probably work well with maybe a half dozen samples. Others like the 109s, or anything with that external whine/whistle could use many more, and I'm just talking engine sounds. You can't do that with what we had before.
I think this new system is going to be the best there is, but it is going to take time.