If one of my fighters is so low on health that he can't survive being attacked, should he flee or continue attacking?
Run away!
Go out fighting!
If one of my fighters is so low on health that he can't survive being attacked, should he flee or continue attacking?
Well, this depends on many things. For example, if it's a tanky-breaky unit, it must surely stand and fight. If it's a damage dealer, it might be worth using him as a meat-shield, so it's stand-and-fight. If it's a support unit (e.g. a Mender), it must surely escape to safety.
Together we stand, divided we fall.
I'd be interested in your reasoning. Factors I'm thinking about are:
1. If he runs away when he has one HP left, he's going to eat up a turn that I could be using for one of my men that can still do some damage
2. If I let him die fighting, he'll have to undergo a rest cure which will slow the group down.
Exactly. Thankfully, you're likely to have more units on your Party and your Roster, to mitigate both issues: cope with turn-disadvantage (if you keep the maimed unit alive) or with injuries (if you let him die fighting).
In one of my "nightmare" Saga1 playthroughs, I was playing on Hard, taking all battles with a 6-unit Party and trying to win with zero KOs (and avoid save-scumming, of course). It was quite difficulty, actually. I think I had a couple of KOs in 2-3 fights, in overall.
Together we stand, divided we fall.