Things may work out,but he rir may be submissive forever,or may stand his ground.Letting the Silkie dominate right now is best.The younger one can view him as power,and not try to kill him as they age.
I suggest at least only having one roo with the 11 hens.And getting the others separate pens with hens.Or split up the 11 hens and split them off to different roosters.
There are some squabbles,but they never are too serious.BUT,roosters will get fed up sometimes and can kill each other (I have had experience with two roo's who grew up together and tried killing eachother.
Usually when roosters are just a few months old,they can figure the pecking order out young (But that doesn't mean it always works out.)Did any of the roosters grow up together?