Three games with four players, one with three. It doesn’t seem like a good choice for two players to my mind, but haven’t tried it that way. Five players might wear out its welcome, but the time/fun balance seemed pretty good at four.

That being said, raider ambushes seem to be a relatively minor part of the game so far. Its rare they can have a big impact on the game (although I did see one case where it mattered a lot to take that one extra point of damage and the exact wrong moment).