Friends First Campaign: should I play an origin or tav?

I’ve got about 400 hours in the game and I’ve recently convinced a friend to pick it up but we want to play a co-op campaign together. To me, the best part of the games are the companions, and when playing multiplayer, it sucks that you lose one spot for a companion joining you at all times. I’ve never played an origin character (other than durge) but I want her to have the best experience possible with the companions. Should I consider playing an origin character so as not to “lose that slot” or just stick with a tav? Pros and cons to playing a companion in a co-op setting?