In many ways, I think Sims was and is misused. Why he needs is a coach ho will take him aside and say, "Son, you are a running QB who can throw. We are going to put in the same O that Caldwell uses and teach you how to work it. You, both, need to get it through your head that you are going to run and you are going to get hit. We'll help by putting you in an O where the D can't tee off on you without getting burned. Now, get out on the field!"
But no coach does that. They look at his arm and release and think they have another Namath on their hands. But he simply isn't an adequate drop back QB. H could be a great run/pass option or disguised veer (that's what Caldwell uses) QB.