It seems that females do not always prefer large-patched males. They adjust their preferences according to seasonal change in the proportion of energy that large-patched males will devote to fatherhood. Males with large forehead patches are sexier and potentially father more chicks, but they are often too tired from fighting to make good fathers early in the season. But defer mating for too long, and the chances of raising a brood fall sharply. In other words, a male that keeps his cool and exercises moderation in all things.
Some guys just have all the luck.