How far below the shoulders can you go?

A big question in my swing is how far below the shoulder line can the lead arm rest at the top of the backswing. All good S and T players bring the club to the shoulder line or above but I tend to slice or top the ball here. I feel more power and control when the arm is set lower (deeper), about across my upper chest. I'm short (5'4")-so can I get away with this? A lower swing promotes and in to out path, guaranteeing a draw which naturally adds some distance.