Aye, Burrell is a better finisher IMO, however, he's only scored 4 when starting games out of a total of 9 (I think). Two of those were in the same game v QotS, one was against Wick and the other in the Challenge Cup v Partick.
The facts are that he's far better coming off the bench when defences are tired and Oliver's better starting because he can hold the ball up well, bringing Morrison, Kennedy, Nesbitt etc into the game.
I'd love to see Burrell starting games, running the legs off centre halves and scoring loads but the evidence points to that not being the case. We've hit upon a formula that's doing well and I think we'd be best to leave it alone.