not really possible to program in the battle generator.
However for AI forces in WinSPWW2, some AI-generated forces will buy historical allied forces. I added a "buy allied formation" routine to WinSPWW2 AI force generation, and this is used e.g for Indian army forces vs GE in the desert and italy to buy UL air, arty, and infantry tanks. Some of the minor Eastern countries will do that with e.g. Soviet tanks and arty in the LWP mix, and GE allies for the RSI Italians and so on. Polish in France get FR support troops. Brits may buy Indian Ghurkas in the far East. Belgians will buy UK & CDN air strikes, ary and tanks as support in NW Europe, Spanish get Italian CTV in the SCW, that sort of thing.
I have not done Italian allies to the AI DAK (as they really fought as separate divisions) - whereas we are concerned with brigade and below in the game.
So if ID tags are on, and you happen to notice "foreign" troops on the AI side - that is not a bug
!
Cheers
Andy