I agree, the keys to keeping multiple boys are numbers of hens and space. We always have roosters around, but rarely get near that 1:10 ratio. Usually we're closer to 1:15 or more. We also have a lot of space.
 
Usually the roosters take very little notice of each other, even roosting together on the top roost. It's almost like an old-fashioned kingdom, with the alpha rooster being the king over all his subordinates, each of whom also has his own little fiefdom. The alpha keeps his favorite hens, and also mates with whatever hens he chooses. The remaining hens are sort of divvied up among the subordinate roosters, each of whom keeps his little flock together most of the time. If the alpha is occupied elsewhere, though, the subordinates might sneak over and mate the alpha's hens when he's not looking. It's kind of funny.
 
Things are usually very quiet except in the spring, which is when that space comes into play. In the spring, the subordinates try to advance their respective positions, They'll try to move up in the rooster pecking order (which is separate from the hen pecking order). There is always sparring and they'll fluff up their hackles and fly at each other, claws and spurs out. I'm sure they'd do real damage to each other without a lot of space. As it is, there is always room for the loser to run away. The winner will chase the loser around and around the pasture until the winner is sure the loser understands who's the boss. We see a lot of feathers flying, but my motto is "no blood, no foul." This only lasts for a few days each spring, until the pecking order is fully established again.
 
Sometimes a rooster will move up to alpha, sort of overnight. It usually happens when a big, strapping young cockerel challenges an older rooster who's been the alpha for several years. In those cases. it's almost as if the alpha doesn't fight it--he knows his run is over. He'll drop down in the pecking order, and his hens will drop in the pecking order, too. The hens belonging to the new king will move up in the pecking order. Reminds me of "The king is defeated--long live the king!"