whats harder with muscovies? size or caruncles

[syble]

I'm gonna have to do some serious work with my to be colored muscovies, the males are easy enough to pick from but the hens seam to be in two distinctions (the same age), they are well masked but a bit smaller, or they are larger with next to no caruncleing. With the aim of being able to produce decent show stock, which trait is harder to breed up? caruncling? or size?
Thanks
Sib