You are correct if you factor in his rushing yards.
Also you just answered my next question, which is since he is a ground based QB that is only good b/c he can work magic by scrambling (not passing) then why should we take the chance of wasting another season by giving him a fair shot.
If Ronnie Brown had an ACL tear do you think the Dolphins would keep him, heck no they would trade or cut him very fast because runners don't recover from ACL's, and the few that do always re-injure them.
DC was a great QB because of his rushing abilities not b/c of his passing skills, if we give him a shot then other QB's that don't want to compete and be part of a QB controversy are not going to think of Miami as an option.