The roosters I have seen engage and repel hawks did not do it to protect their "ladies", rather they were protecting their offspring. The birds putting themselves at risk had a history as in a social group with the vulnerable immature birds. Harem masters are the ones doing it, not just any old rooster among many that might out with a group of hens. Breed may also be important. My pure games and Missouri Dominiques (hybrid between games and American Dominiques) go after hawks readily part of year while American Dominiques have not demonstrated capacity to do the same yet. The seasonality part is also very important where mine go after hawks between roughly February and July. Mine are also much more confident when they can operate from cover where hawk can not get above them. Some of the games more flexible on the latter point. Hawks we are dealing with are definitely targeting chicks / juveniles small enough to fly off with even when alive. Roosters can shut that down here.