My companions aren't all that useful in a fight, generally speaking, but I can't just leave my doctor, quartermaster, and pregnant wife back with the baggage train like any sane commander would.
That means I have to try to keep them from getting killed. The best way I've found is to either give them a bow and surround them with Fian Champions or give them a horse and have them follow me. I wouldn't care that much if they were just brawlers - those are a dime a dozen - but doctors and traders are hard to find.
Why do I have to bring noncombatants into combat at all...?