Chariots, Elephants, Mammoths you would put in the largest Squad with the best Morale and have them shore up the center if they have lower morale.

Hydra's you are just screwed, have them attack archers or rear while putting them quite far on your flank so they have a chance of not running into the main host and actually not killing half your army.

Behemoths with no morale issue on a flank. Others have other orders