IMHO there are many nice things that could be changed. The problem comes, as Matthew_Baker says, when the current balance is broken.
The game has limitations. Here are a few examples.
Tanks can be considered weak against the infantry because:
1) They cannot destroy any static buildings in which the infantry hide.
2) Spawnable AT kits. A regular soldier can respawn with an AT weapon soon after being killed by the tank.
Tanks can be considered strong against the infantry because:
1) A single person does everything: driving, shooting, spotting, communicating. Reactions are very fast.
2) Turrets move faster than in real life.
3) They can get fully repaired in the middle of the battle in just a handful of seconds.
4) They respawn fairly fast. There is no major punish for losing a tank.
I think that in these kind of matters, a balance should be kept. For example, if wrenches repair up to 50% then infantry AT kits should be more limited to compensate for the lowering of the tank´s value. If repair pads at mainbase are to be used then double (at least) tanks´ respawn time (to make driving back to main worth the lost time) and limit even more the availablity of AT weapons to compensate the fact that tanks will become more rare in the battlefield.