Your original breeds are large fowl birds. They will have a considerable size advantage, a number in the flock advantage, and home turf advantage. The fact they are very young might help, but might not. I would expect them to be fairly aggressive to the silkie and polish.
Some people do get the tiny breeds to live with their flock without a lot of problems, but some report horrible problems, even merciless pecking on the little ones because they look so different. If this is your first year, I would recommend passing on them. They are apt to add a lot of problems to your flock.
A huge amount depends on your set up, how big is your coop/run, how do you have it set up. More space is better, but in getting two groups to get along, it becomes imperative. For 8 birds, you need a coop about 32 square feet, so 8 feet x 4 feet. The run should also be about 80 square feet. It should have hideouts in it, escape routes, and roosts, not just an open rectangle.
Posting pictures can help, but neither flocks are full size, and it is almost hard to believe how much bigger they are going to get, while the coop stays the same size, my point being that what seems like a lot of space now, may very well not be enough space shortly.
Mrs K
