What I've learned through threads, reading Storey's guide and other books and from the people in my area is that the Alpha rooster will get with all the girls he can handle, but physically he may spread himself thin in the process (i.e. not all the eggs will get fertilized). My neighbor has dozens of chickens, mostly roosters and only the alpha really gets to mate consistently. Of course, they have lots of room to roam and the hens can easily escape the advances of the roosters so the hens don't show feather loss on the heads and backs. Another problem lies in whether or not the hens get stressed out from too much attention. If they do they won't lay. I have one rooster in his prime and he has his choice of 7 girls his own age, but stays with just one. (I think its because she's easy, where the others fight and squawk). She is the only one I have that lays and lays everyday.
I got caught up in the whole rooster needs enough girls issue too and ended up going from 1 roo and 4 pullets to well, 30+ chickens.
If you only have one rooster and enough room for the girls to escape, I wouldn't worry too much and if necessary you can always seperate the rooster.
