As title says. How to force them to make vehicles when tech level is UNDER aircraft? I can't stand seeing Yak WW2 planes hover. (sorry I know game engine restrictions)
I run the game on Free For All every faction on a custom testing map to test the AI for what map nuances cater to which AI. Mainly because I prefer to make ground vehicle maps.
Also, if a dev/modder see's this post. Think of a way that infantry can cross all terrain where vehicles cannot.