My impression of serious injuries is that you can never have too much antibiotic. At the risk of over-preparing, I can imagine a lot of scenarios where not having a way to prevent infection is a very bad thing, which to me makes it the only thing to bring extraneously. Bandages can be improvised; antibiotics can't.
My worst-case scenario is slipping on a fallen log and getting a gash or impaling injury on my leg. I think I can reasonably prepare a first-aid kit for walking out of that or a similar injury and then count on using my head and staying put for anything worse (and normal precautions like telling people where I'm going.) In the event of that injury, my solution is to use the wound closure strips, gauze, an improvised covering along with the ACE bandage, and a hefty amount of Neosporin to keep the wound clean and infection-free for a few days of travel out of the wilderness. In that case, I might use 3/4 of a tube over two or three days.
My logic; if it's flawed, don't hesitate to say so. This just felt like 1-2 ounces that were graciously accepted to put my mind at ease, but experience could correct me.