Some others, like 
@RebeccaBoyd and 
@rural mouse , probably others, can chime in here as well.
In my experience, you generally need 4-5 hens for 2 or more roos.  That said, I have had  hen hatch 4 chicks, 2 & 2, and they were absolutely fine together.  In short: it depends!  It depends on the temperament of the roosters, the keeping arrangements, and the hens themselves.  Each rooster really needs at least 1 hen that has accepted him - otherwise he will always be fighting the other rooster (mainly because the other rooster will be 'protecting' HIS hens from the mating advances of the rooster with no hens). 
With a young boy, expect him to go through his hormonal idiot stage.  As long as he isn't harming you - and somebody (hen or other roo) teaches him the ropes and gives him a smack-down when he is inappropriate...AND he learns from the 'smack-down', it should be fine.  Some, as 
@rural mouse learned, just don't have the tempermant to accept multiple roosters/settle down/smarten up. 
 Yet she has others that are perfectly fine in a multiple Rooster flock.