So we had two big traveling merchants visit our colony and a fire broke out. The fire was huge, and devastated most, if not all of the colony. The merchant bands did nothing, there were at least a dozen of them, and they sort of just side-stepped the flames and wandered around all, "Huh, sure is hot here. You guys got this right? We'll be over here."
I know merchants will sometimes fire on bandits, but only if the bandits attack them first. There really needs to be a passive priority for non-colony pawns to assist with big emergencies that otherwise impede their 'goal'. We can't trade with you if there's nothing left to trade with.
They should help with medical emergencies too, suppose you just beat a big raid but 5 colonists out of 8 are down, and there's only 2 doctors left. (1 person can't doctor for whatever reason.) If this happens, you have to pick which colonists are worth treating/rescuing first. I don't think it would completely unreasonable for a visiting trader to at least pick up downed colonists and bring them to their respective beds. Maybe there would be a popup thing saying, "[visitor name] has rescued [colonist]. He/she is offering to treat [colonist], and his/her medical skill is [n]. Accept/Decline?"
Since you can do the same for the traders it would be really nice