I'm more than half of the opinion that the Kiffin hire was for a last-hurrah season, anyway. I didn't like the move at the time, but it's pretty hard to blame the guy given how badly the DL was decimated from the get-go. It's not like Marinelli and Garrett were sitting around deciding how to make the playoffs and were reluctant to say 'play more single high' just because of the enormous respect they had for the old man. We didn't play the press coverage and bring the S up because we couldn't get the pressure late in the season and we couldn't leave our LBs in coverage once Lee went out. We were hamstrung, and the organization had to know it.
And I don't see Marinelli agreeing to the position promotion over his old friend in his final year if that wasn't something on the table all along.
I guess there are a couple of other ways this could have played out, but I think it's more likely that some sort of transition plan was in the works all along. Now, I think that, in itself was probably unnecessary and stupid, but that doesn't mean I don't think it was part of the discussion in bringing the 4-3 press coverage defense to Dallas.
Either way, I like Marinelli, and I really like this scheme the way it's meant to be played, so I'm happy with the result.