Jock,
At the risk of re-opening the "canting" debate (which I won't participate in simply because I think it is largely a silly discussion), and with the disclaimer of this is MY OPINION ONLY... Here goes.
In the system I teach, once the shooter has gotten to full draw, a relationship between the posture of the shooter and the head position with the bow and bow string is established, the archer's "T". At this point that relationship is maintained for the aiming step. This is where the moving of the "T" by moving the body and NOT the arms or bow hand independently comes into play. As discussed above, setting aiming elevation is done with a sideways movement (bend at the waist or "kick the hip out") while maintaining the "T".
By moving in a "bowing" movement, you can 1. get your eye over the arrow nock, 2. bend to a point where the bow is nearly horizontal, 3. bend so you can shoot under a low branch, etc.
Really look at some of the "old masters" where they appear to be "canting" the bow. But look farther and with more detail. Look at the drawn string in relation to their eye, look at the string and how it aligns to their head position. I think in MOST cases, the body/head position sets the "Cant" of the bow and not just the bow hand.
Before anyone "jumps" to the "you never could do that hunting" argument, I suggest that this is a TRAINING type practice to LEARN the technique and feel. Once LEARNED all that can be done more directly and with little movement, but that is another discussion.
Arne