It seems a little extensive for that, but I think it could work. Although I don't think other zombies could have done that damage, it's very likely that survivors could have shot him up. Although judging from the movies, blaster fire doesn't do that kind of damage. Perhaps he did battle with a Rancor.
Or maybe that's what turned him into a zombie, he had to fight a zombie rancor who ripped his armor to shreds before infecting him. Man that would be a hell of a story.