Will chicks fight with other chicks if put together?

it depends on temperament, breed, age, and if they came from the same clutch of eggs.

in other Words, put them together and watch what happens - if they get along leave them together, but keep watching anyway just in case - if they fight separate them again and don't try it for a while.

try it in small groups - just a few from each - equal numbers!

Yes, chicks from different broods will practice the pecking order based on age, condition and size. Even chicks hatched a few days apart will chase each other around and try to establish dominance. Whenever possible keep chicks together in groups and when adding to the flock expect some scuffles and fighting. Hatcheries de-beak (remove the tip of the beak) new chicks exactly for this reason.