[Suhiir]

Tank fire support may well be influenced by the type/amount of main gun ammo.
If all they have is AP/Sabot/HEAT they might not have anything to fire at infantry.
They will fire HEAT at infantry IF their supply of it is large enough (and don't ask me how many rounds "large enough" is) but some will always be reserved for armored threats.

I'm not sure if reducing the carry capacity of APC/IFVs will cause them to stop their eternal "pick up infantry - drop off infantry - never move an inch" ballet. I believe their unit class dictates this behavior and the carry capacity ONLY determines how much they can carry.

I've had a certain amount of luck with making infantry and vehicles separate formations. IF they dismount in sight/range of an unoccupied victory hex they'll act fairly reasonably IF you plot them to go in different directions after the dismount. But they still have the problem of moving about one turns worth of movement points, dismounting, then spending the rest of the scenario just sitting there doing the load/unload ballet IF they're to far (and no clue exactly how far that is, seems to be 20+ hexes) from an UNOCCUPIED victory hex.

I really wish you luck finding a way to deal with this I've been trying everything I can come up with and no luck.