ST. In fact looking at his resume, he has never coached them as far as I can tell. At least Jackie coached them at some point in time before coming here. I'm kind of puzzled as to why a guy who is an OC wants to coach them.
If we had another HC who wanted to also be the OC, that doesn't mean that he will be the next Steve Spurrier. In fact typically, a guy who wants to coach a certain aspect of the game usually ends up failing miserably at that aspect because they can't handle both HC and coordinator duties. See Coach O as HC and DC. So, even if we were VT caliber on ST under Jackie at one point in time, that doesn't necessarily mean that Mullen is going to be a great ST's coach.
Again, I don't understand why we can't find a coach that, you know, wants to be the HC like 95% of the teams in the country.