Skill in aggression will be needed from time to time, especially by those lacking skill and will. The solution is to ground aggression in a ritual expression that also prepares it for functional application. Aggression has three purposes in nature. First, to spread a species out over territory so as to not overload an eco-system. Second, for rank within the hierarchy of a social group.
All social groups have hierarchy.
And third, for reproduction. Classically this means two males fighting over the female, but it also means the female defending her young. If there is no social unit, e.g. Siamese fighting fish, it does not matter that the loser dies, only that the winner breeds. In contrast, in social animals, there is a strong biological benefit if the second and third types of aggression do not damage the loser. Young males competing.