I actually would try to use the hen for the CX side, A smaller rooster does less damage to the hen, of course that only matters in f1, Beyond that you are going to have huge birds.
Unless, you are bringing in a third line.
I do not think it makes a lot of difference as the size and rate of growth which side is which. I know there are people that would argue with that and say the rooster is 75%, but their are people that would say the opposite too. I have just not found a lot of difference.
If you want to hear something weird. Remember when I first put this generation ( the first group) outside into their pen to "free range". I picked a black chick at random., and put in with them to "teach" them how to be chickens.
He has the body shape and size (almost) of a Toad! He has no toad genetics in him. I have asked him why he looks so weird. I told him DNA does not rub off the Toads to him. I will try to get you a picture of him, if the fog goes away and it ever quits raining. The bird does not look at all like his biological brothers and sisters. He is fed a skimpy amount of feed compared to my other birds. Just unexplainable to me.