People are individuals. I think people with strong Se are comfortable with confrontation and aggression if it seems necessary, but that doesn't mean that any given person with strong Se would be aggressive in normal circumstances. How aggressive someone with strong Se is depends on the person and the particular circumstance.
So I think they understand it, they're comfortable with it, and they are capable of using aggression if they find themselves in a circumstance where it would be helpful. But they aren't necessarily running around being aggressive on a regular basis.
I can see how that would be useful because there are times I'd like to be able to confront someone and be a bit aggressive but I don't feel comfortable with it.