Bob, Happy with that definition as the Purple Book goes.....
However, I am taken with Tony Aguilar’s thoughts about Hannibal. Almost always on foreign soil so - Aggression should be high BUT almost always fought on terrain of his choosing - so Agression should be low.
Aggression conflates two situations: who is invading the home terrain of whom and the tactical defender forcing the tactical attacker to fight in the terrain of their choice. I don't think that does a good job of reflecting the dynamics of armies, especially armies with competent generals and good understanding of military techniques, trying to out-manoeuvre each other into favourable positions for a battle, as the Hannibal example shows.
It seems like an easy spot for a house rule "fix".