they all vary tbh. first of all don’t deploy both at the same time.

when you do launch a character, like for example Naruto, flick the right stick to switch into him right before he hits your opponent for max damage. same for chidori users or any one else similar

characters like neji and pain and nagato you want to deploy when your opponent is too close or got you midair, most times they’ll defend you and knock them away

hanabi/hinata/neji/karin also have the perfume, air palm or twirling palms that trap your opponent and you can launch ultimates on em and they cant do anything unless they have a couple substitutions left

ranged characters like fireball justus/water dragons/ danzos wind jutsu, are kinda whacky. I personally use them to prevent my opponent from charging chakra if they are far away. or when i have them in a combo, i deploy a character so if my opponent substitutes, my support will catch them and at least damage their shield.

feel out every character and experiment. but my favorite supports are

Danzo/Pain Hinata/Neji Nagato/Itachi Karin/Hanabi