I get told quite regularly that I'm bossy. But I'm a girly girl. So instead of assertive, I'm bossy.
Actually, when butches *do* tell me I'm bossy, they are usually flirting (which is rare. mostly they just don't speak to me, full stop. Or are excessively polite, which I have no idea how to play with). I usually follow it up with "Yup. I sure am."

then they laugh and tell me they like bossy/feisty as when I go down, I will go down with some sweet fun to it. That's the kind of answer I like. It's a challenge. It turns into a "Oh yeah?" "Yeah!" "Well, c'mon then if you think you're so hard!" kind of playful argument.
Though one butch dom I dated told me she could not abide bossy girls or amazon types. I knew it was very short lived.
I have told my exwife on quite a few occasions to chill it. I called her my Dutch Doberman. But it's not because she was butch, it was because of her very assertive personality and she's dutch lol so she will point blank tell someone they are a cunt.
I rather liked that quality about her but I did have to drag her off by her ear at times.