REALLY CLOSE: Red fox. The big problem here is that they're competitive and ambitious. Goddamn.

Relatedly, arctic fox has the opposite problem: the one trait that's off with them is that they are the opposite of assertive.

Those are the two closest fits so far. I'm gonna still be looking, but I wanted to throw these your way to see if you think either of them are actually usable!

ETA: Gray foxes seem to be a middle-ground?