I don't see his form in France as being particularly relevant as the game is different there (slower and less physical). Cole has stated as much himself on a couple of occasions.
I guess the main difference between then and now is that whilst under Roy he often received the ball on the half way line with his back to goal in that god awful defensive setup, Rodgers will more likely play a possession game that will suit him far more. If we can get him facing the goal in the final third he may be able to inject some of the creativity we were sorely lacking in last season. He doesn't need pace to do that.
Obviously still not convinced but I suppose we don't have too much to lose by giving him a shot.