Don't agree - good players don't need leadership, they lead themselves. If you need leadership, you're going to get, well, not that far TBH.
Experience is hopelessly overrated. Essentially it derives from the (ludicrous) idea that younger players don't know how to bat or bowl. Often it's mistaken for the fact that players get better (not more experienced, just better) as their careers go on. Jaques, though, didn't need to - he was already a top-standard batsman as he started his Test career.
Ability, not experience, is what counts. There are some young players who are a bit stupid, but if anyone's telling me most young players don't know where to bowl the ball, or how to bat well, they're mad. But ability can, and very often is, improved throughout a player's career.
And how about when he had Greg Mail or whoever at the other end? Still seems to have gone pretty damn well then. In any case, he's scored loads of runs after Hayden's been dismissed.
I don't think Jaques is a poor enough player to be affected by who's at the other end.