point is, if you can't use healers, why can you hire them?
That's a good question, one that I had not pondered. How about this: if you get sick because a region has no food, the healer works then? Or if you get stabbed by someone tired of your preaching? Beat up by a mob? Trip on a rock?
It would be cool if you could bring healers along with you and they were useful to the people around you, but I wonder about the benefits at large (plus coding effort vs. game usefulness).