When considering the axis of creating super bugs, cocktails would probably exacerbate the problem, since now you're applying several stressors in parallel. Unless you had like, 5 or so fundamentally different avenues of attack, then you could get, what, 30~ unique combos? Most people don't need anti-biotics more than 10 times in their life? If it they were equally valid in any case, doctors could just choose randomly from the set of cocktails they haven't used on a given patient before. I'm certain a cell biologist would tell me this is a dumb plan for some reason, though.