Thx for explanation. It will be a while till I get to 5-4 though. Hit a bit of a wall in late chapter 4. Gotta upgrade my equipment a little. Hopefully I won't have to redesign my unit combination.

Also - are there any hidden dungeons in chapter 3 and later with some fancy rewards? Or hidden dungeons are just a way for you to easier farm unit upgrades and some generals in prologue and first two chapters?