Where are you located? If you are over in Europe then he could be a large fowl Silkie and they are of course bigger than the Bantam version. Large fowl Silkies are not common in the US.
Those buff birds look like a d'uccle of some sort. Do you have Bantam breeds? Your Silkie might be a standard size, or large fowl (LF) Silkie while your other birds are bantams.
I'm really curious, what's that red thing over your clothes line??I have large silkies, working on making Giant Silkies.
View attachment 2352541 View attachment 2352542 Standard sized Silkie Rooster vs Bantam Silkie Rooster.
He's the same size of a regular LF chicken.
I have a few more that's abit shorter then what he is.
He's also a pure silkie.