from the cornish x orpington they look just like hens with white and orangish feathers but were more heavier than my other breeds and eat more than them too but calm and gentle.
Sounds like a good Idea might work. We did a similar cross where we crossed a buff orpington rooster with a cornish cross hen. Got about 6 chicks 5 hens 1 roo now theyre are 10 months larger and heavier than my other chickens. The rooster weighs about 10 lb. Not too bad. Good luck keep us posted.
What my uncle is doing to breed cornish x rock is he separated a cockerel and 2 pullets and they have a seperate pen he keeps them on diet so the roo wont get too heavy and would be able to mate with pullets. So far they're about 4 months and doing good.