The whole "skill > experience > gear" thing does work.... but there isn't a massive difference between their usefulness. Experience is just as easy to gain as gear, and skill will come with experience, so they're all linked, and all will increase proportionally with your playtime/reading time.
As an example, Itchi is now *technically* the best geared tank in the guild; I in no way consider myself to be the best tank however, as he's an alt, and I've only ever done 2 ICC10s, a ToC25, an Ony10 and 2 Naxx10 runs. Apart from those Naxx runs, and the Ony run, all of those raids have been done in the last month.
The gear is very much readily available via heroics now, and whilst I must admit I was grinding the hell out of them to help Janco gear up, we only spent a week or so doing a couple of hours a night, and Itchi was geared to how he is now. I've hardly spent any time on Huung since 3.3, and yet his main spec is almost as geared as it can be via triumph (bar things like crafted bracers).
My point is that even with a lack of experience, being overgeared to the back teeth for the instances we're doing makes up for it in the short term, until the experience can be gained - especially if the raid includes people who are experienced in their classes. I'm not saying carry people through, but I'd like to think I'm not a total nab when on the tankybear.