This is a good one. Mine usually take cover and heal to full, but it's situational.
- If there's a hut visible to the unit and no visible barbs, I'll usually go straight for it no matter how injured.
- A warrior that I want back for defense is extra-cautious. But he might run home injured, if he's already close.
- Likewise I rarely do the Woodsman II thing. I usually go Combat and eventually try to bring him home.
- A scout at .7 or .8 might just keep going, especially if
--- he has a chance at more huts,
--- and/or I need to explore another pie slice around my capital,
--- and/or I know he's going to get eaten by an Archer soon anyway.
- An exploring scout/warrior that's distant but has been around for a while I usually just write off. I'm probably chasing techs other than Writing for open borders, and I KNOW he's going to get eaten by an Archer. I might automate him. By this time I'm getting lazy and am much more interested in the details of my first city or two (which are probably getting pounded by barbs) than in having to keep scrolling to a remote part of the map just to explore one more tile.
- I usually move scouts two tiles, even at risk. Rarely do mine move one and stop.
For the past while I've played Emperor/Epic, and if I start with Hunting my experience is generally that that my scout (and second scout, if I start by building one) can get a few huts, and that even a warrior can get one or two.