I think the biggest problem with "Bob" was not the choice of actor, but rather that he was a completely generic bad guy. I don't remember Tige Andrews having a huge range as an actor but, aside from the uniform and off-camera "Klingon activity in the sector," the Kras character as written is pretty much indistinguishable from "Cardboard-cutout thug #1".His take on any of the three “main” Klingons would not be what we got. Might be an improvement on “Bob” though.