Depends on the writer. You get a superman DC writer, homelander probably gets treated like every other fascist superman beats up. If it's a "the boys" writer, homelander probably uses kryptonite to rip superman in half in a graphic full-page spread or some shit. You're also gonna be dealing with, are we dropping superman into the relatively hopeless universe of the boys, are we dropping homelander into the DC universe, where he'll probably be right st home with like 30 different characters almost exactly like him, will we come up with some portal stuff, what's going on there

So I dunno, depends on the writer. Ke personally I'd prefer if superman won, cause it's more hopeful and less garth ennis-y.