I am not a bow hunter, but I have several years experience in orthopedic rehabilitation and I am currently earning my doctorate in physical therapy, so only take me partly seriously. Here are what I think might be some helpful and encouraging points for you to consider:
- Your rotator cuff's (RC) primary purpose is to produce rotation of the upper arm (think more like throwing or swimming motions), and to keep the bone of the upper arm stabilized onto your shoulder blade.
- In a draw, there is minimal rotation of the upper arm, it's not a windup motion like you're throwing a pitch, so... it is your deltoids, pectorals, and biceps, not your RC, that are primarily responsible for getting the upper arm horizontal and parallel to the ground
-The other muscles mostly responsible for your draw mechanics are not part of your RC complex; rather your lats, teres major, and deltoids are
- The muscles acting on your shoulder blade (traps, rhomboids, serratus anterior, and levator scapulae) are the MOST important. The muscles of the RC all originate from the shoulder blade, so if the muscles actually moving the shoulder blade don't work well, it cannot move into the correct position to allow your RC to function properly, and you get faulty shoulder mechanics, which is probably how you came to encounter RC issues, or other injuries, in the first place.
Overall, your RC isn't responsible for getting you to full draw, but it does play a massive part in dynamically stabilizing your arm in that spot once you get there, and it helps while you hold for the shot. If you have surgical repair, the RC is after all only a group of four muscles and their tendons, so it heals fairly well (labrum, ligament, and bursa issues are another topic). Follow your surgeon's advice and go to your PT appointments. Getting your range of motion back is the first step, but you will eventually regain full strength of the muscles actually needed for the draw. Your PT will also get the muscles acting on the shoulder blade to adequately function, then your RC is in a favorable position, and then they'll rehab your RC so that it can maintain your draw. It won't happen overnight, but if you do your part, you'll get back to bow hunting sooner than you think. Treat your rehab as seriously as your hunting, and you will probably have improved mechanics when you're ready.