cockerel covered in blood, been fighting. What to do?

I have just gone out to see the chickens and suddenly it seems the fiarytale stage of owning chickens has ended and the nightmare begun. Two of the cockerals I have that were hatched on the same day and have been raised together have decided to have it out with one another. One is a maran and the other a light sussex. The light sussex seemed to be worse off and was seen on a few occasions walking away from the maran which tells me its the maran asserting his place in the pecking order. For sometime now the light sussex has been top dog. Anyhow I have seperated the maran to a coop and run that is 20 metres away and they are all crowing like mad. Personally I think the maran eats too much and isnt doing the business with the hens, unlike the light sussex which is doing the business several times a day. So should I condem the maran cockerel?

Im interested to hear your thoughts/comments on this situation.

Thanks

Thanks for the reply Joyfull and thanks for the tip about the cornflour. The maran is related to a couple of the hens whereas the light sussex has no relation to any of them however I have no light sussex hens. I wanted to keep a couple of cockerals for breeding from just to get my flock numbers up. Do most people in this game keep the cockerals completely seperate from each other?
The light sussex is more heavy handed with the ladies than the maran but then the maran is huge and seems to scare off the hens hence why he doesnt get much lady luck. The maran is also quieter whereas the light sussex is the noisiest out of the lot. Im guessing there is a link between noiseyness and testosterone, can anyone confirm this?

When you say to keep them seperate which one should I take away from the others? The bully or the bullied?

Thanks

I hatched 3 marans in total, 1 male and 2 hens. So they are brothers and sisters.

Problem solved! well for now anyhow...

The Maran cockerel is now hanging in my shed upsidown with no feathers ready for gutting tomorrow. Although none of the other chickens saw me do this one of his sisters does seem a little worried as to where he might be. Will it affect her laying?