I don't get calluses anymore. My fingers hurt for maybe 6 months after I got back into traditional 5 years ago but not now. It's my feeling that if you have finger pain, calluses, etc. that there is something in your form that isn't right, your bow is causing finger pinch, and/or your finger protection is not adequate. I do know that a high string elbow will cause a big problem with your ring finger, as will a cupped string hand, being overbowed, etc.
I shoot modified Wilson tabs and all my bows are 66" long and drawn to 28".