re: Is it possible to change offense philosophy at this point?

Yeah.
No, it's it highly unlikely to change.
First, because Leslie is not inclined to change it.
He is a run- first guy who has never seen an opponent's defense which didn't call for a scheme to run right at them. He like athe carpenter who solves all problems with a hammer and a nail.
And, here's the rub that some refuse to acknowledge: It has served him extremely well to have these prejudices, b/c he wins more than the other 90%.

The problem is 1) sometimes we have won DESPITE Les and 2) the game, our opponents and our personnel change.
We are not talentled or experienced enough this year to win despite the handicaps of a poor scheme going into a game.
Nor do we have an experienced QB to bail us out at the end, at least in SEC competition.