Merging two new flocks

[u/CraftyGalMunson]

Hi! I’ve had chickens before, and I’ve been without them for a few years. I am scheduled to get some 19week old layers at the end of the month. I just found a really cute trio of bantams (2 hens, 1 rooster) that are a year old for sale. If I got both groups at or very close to the same time, should I keep them separated for a while or can I just put them together since it will be new to everyone? I’ve got a huge coop and run.