The only time I've run across people who were having trouble drawing equal weight with a release as fingers was becasue they were trying to draw the bow purely by pulling on the string (you can't pull on the string as well if you haven't got a grip on it). It should be an equivalent push and pull motion incorporating the back muscles more than the shoulders/arms. It's hard to describe but try drawing it by pushing the bow away from you rather than pulling the string to you and feel the muscles at your scapula while you do it, those are the muscles you want to incorporate.