Keep in mind that if you used to use a finger in the corner of your mouth anchor, and if you now use thumb knuckle touching the earlobe, the rear end of your arrow is further to the right than it was before. Thus, if you desire to keep your eye over the arrow, you will have to tilt your head slightly more than you did before.
Rick believes all adjustments, to the extent possible, should be made with the bow, and not by the shooter. Following his method, you should try the Martin rug arrowplate, and if that doesn't give you enough adjustment, you should try a weaker spine. In fact Rick himself generally uses a weaker spine than recommended.
Far be it from me to argue with Rick, as his method has proven successful for himself and many other people. I learned how to shoot better from attending his class than I ever thought was possible. But for me, if my eye is over the arrow, and the arrow is tuned for the bow, it will go where I'm looking, so to that extent, I've altered his method.