To whit, despite your claim above that your modification to shield master incrementally increased realism, it really doesn't do so at all. It remains just as gamey as it was before, you've just modified the rules a bit. It's functionality to the game is improved, as it now benefits the user more directly in game terms, but it hasn't noticably increased realism at all. It has improved your feeling of internal consistency, but that's not synomymous with realism (even if they may often correlate). A magic system, for instance, is not realistic, but removing contradictions makes it more consistent.