@FerrisWheelTrain
In the nicest possible way I think you may be over thinking things like this in regard to your children.
Being aggressive is not necessarily linked to gender conformity or non-conformity, and it is indeed this view that is causing alot of societal issues right now, so I kind of get where you're coming from.
Having said that, statistically, males as a class have a higher incidence of violent behaviour with serious consequences than women do, and it does neither sex any favours as both men and women are the victims, so it makes sense to identify and hopefully change societal and environmental factors that influence this.
Having said that, I have been aggressive myself when backed into a corner, and have experienced aggression from other females - it's not so much about capacity for aggression, but how society engineers things to apparently make it more acceptable for one sex over another.
The solution starts with teaching children that feeling these things is natural depending on stressful situations, but how it is expressed and managed is vital - neither sex should be swinging punches, or pushing or shoving.