JazzG Gabriel's the one covering for the entire backline though and usually leading the unit. Plus most of the time he's covering two positions and not just his own because our left backs over the past 3 years love a wander (except Hincapie).
Saliba's class at stepping out and generally a classy player but I wouldn't be comfortable with him being our leader at the back.
In reality it's great because the two of them complement the other perfectly.