Apparently cheerleading combatants, and responding to those cheerleaders, is literally in our genes:
A study has found that female vervet monkeys manipulate males into fighting battles by lavishing attention on brave soldiers while giving other males the cold shoulder. After scraps with rival gangs, usually over food, females would groom males that had fought hardest, while snapping at those that abstained.

Female vervet monkeys  have been seen manipulating males into fighting battles by showing active males more attention and snapping at those who sit out the fight When the next battle came along, both those singled out for attention and those aggressively shunned would participate more vigorously in combat, according to a study published in the journal Proceedings of the Royal Society B.
That would certainly tend to explain the female preference for Alpha males.