Introducing new chicks... Store-bought vs hatched

I've got a mixed flock that includes two bantams and nine other regular sized chickens. All of various colors and breeds... We have a little of everything.

I recently bought another 11 chicks, also of various breeds. They're about 6 weeks old and have been moved into a brooder box inside the coop, where they are safe from the big chickens but they can see each other.

At the same time, I had a broody hen hatch out three eggs. Those chicks are now about 3 weeks old. I've kept the momma and chicks in a separate pen so far, but have been letting them free range with the older hens during the day.

So far, the older ones pay them no mind whatsoever. The momma does tend to keep them away from the bigger ones for the most part, but when I throw out treats she'll bring them over and they'll get snacks.

My question is... If the momma and baby chicks are okay with the flock, will the store bought ones also be okay? They're much bigger than the hatched chicks already. And some of them are the same size as my adult bantams.

Just wondering how this works with such a mixed group! I know the recommendations are not to introduce until they're all the same size, but that doesn't apply to my hatched chicks and it's kinda weird to see them out and about while the others are kept locked up.

Ideas? Experience?