I keep mine at 1/2 square foot per bird with 1 male per 5 females and they lay extremely well and it is extremely rare that there is a fight or a hen with a bare back. With a pen that size I would probably end up putting 20 hens and 4 Cocks in it. I realy don't see why I should get a lot lower fertility of the birds for the sake of adding one cock bird when all that will happen is that the fertility goes up.
I don't see the point in continuing this back and forth. We obviously have different viewpoints and we aren't going to agree on this. But hey, that's the great thing about BYC. You get to learn from lots of others about what works for them and then decide what works best for you and your situation.