At the very least, people shouldn't equate "complimentary" with "not as important". Erik Karlsson was able to be a game breaking talent for us because he had Marc Methot who was a wicked complimentary defenseman that was able to play in a way that allowed Karlsson to play at his best.Defensive players get labelled "complimentary" when really they are doing most of the heavy-lifting, at least on the back end.
Zub is also a clear step above Jensen, whom is five years older than Zub.
Zub very much is a #2D in this league. We are very lucky to have him. This guy can do most things, even score breakaway goals, but since he is our most defensively-reliable player (stronger and more physical than Sanderson) he takes on the less "flashy" duties.