S! Lazs
If you are saying don't desert your buddies in melee, no a pilot didn't. As long as he could see his wingman or members of his Squadron and they were engaged, then he tried to fight with them, using the team tactics he had been taught.
However, as soon as he lost sight of friendlies...
Most airforces, (I know the British , U.S. and German) told their pilots if they were separated from their wingman or Squadron to immediately exit the combat area and either try to rendezvous at a previously agreed location, or return to their home base. They were absolutely not to stay and fight alone unless they were compelled to.
This combat doctrine was based on the simple fact that survivability of an individual aircraft in the air to air enviroment was low. The odds just didn't payoff to fight alone.
Of course it is a lot easier to spot your buddies in AH than in RL. Those nice green nametags over their head help.
As far as improving tactics in the MA:
I don't know. Haven't been there for a while. I do my flying in HTH, and usually in a Team server. Based on my observations of that enviroment and the enviroment I saw in AH's MA when I was there, I'd say more team flying would payoff for the side which employed it. Of course you probably couldn't get together Squadron strength units, but it seems to me that a 4 ship Flight, using Wingman tactics and coordinated attacks would be quite successful. It sounds like that is practiced by certain Squads on a fairly regular basis. A larger number of pilots, say 8 or 12, using those tactics would be devastating.
All sides used formation attacks, even when they were Japanese flying Zeros or Brits flying Spits. The only difference was that the Brits might follow an opponent through a few more turns than a German might.