I don't have any experience of Silkies but will share this with you. A friend of mine, and I, went to a poultry sale. We bought some Black Rocks and he bought a couple of Silkies. At our house, we sorted out who was getting which hens and his BR and the Silkies went in one cage. The BR were twice the size of the Silkies but it was quite clear that the Silkies were boss.
We've always tried to keep new birds separate from the existing flock for a couple of weeks, but preferably in sight. This is just in case the new ones are carrying anything untoward. Then we put the new birds in the run with the existing flock but in a seperate run / house and corn them together so they get used to each other. Then we move the new birds in at night.
To be honest, we've also introduced new birds (after quarantine) straight in with the existing, but always at night, and I haven't seen much different in behaviour. There's always a bit of scuffling as they sort out the pecking order but just keep an eye out for persisitant bullying. If all the hens are healthy and have room to run away, you shoudln't have a problem. If you have a cockerel, he'll sort out any nonsense.