Around the time the Marine came out, his gimmick changed for no reason from "white guy who thinks he's black and 'street' even though he's from West Newburry, MA" to "guy who thinks he's a marine, cause he played one in a movie, even though he apparently cant even salute properly"
So, he traded one terrible gimmick to another, even though what he really needed was to learn how to f**king wrestle, not a gimmick change.
Oh, and if you cant tell the difference between 90% of the wrestlers just by looking at them, you're blind. No one really looks the same. Put Jeff Hardy next to The Undertaker next to Shawn Michaels next to Randy Orton next to CM Punk. They all have radically different looks.