In the Past, my frizzle cochin bantams always hatched out other breeds for me, they were great mothers.
You are right, a very good mother will take on any chick, but those are rare, specially in the big breeds.
Right now, I have 1 really good Blue Wheaten AM hen that hatched out some chicks for me and she is a good mother. Would she take on other chicks... not sure at this point.
I have some d'Anver hens, that are super good broodies but at most they could only handle 2 full sized chicks... within a couple of weeks the chicks would be nearly as big as the bantams.