This is the kind of thinking that gets you into trouble. you don't need a huge FAK, but "just a day hike" can still lead to serious injuries. I have seen and treated lots and lots of examples.

Some kinds of terrain can produce more injuries than others, as can some activities. perhaps that is a better way to go about your planning. i am a great fan of elastic bandages, some serious sterile bandages, and the ability to improvise (bandannas are great). Most important is your training, which is weightless....