Thank you both!
That really gives me some things to think about as I am going into battles. I've done a little bit of grinding on a couple of maps (playing on normal for my first time) as I noticed that certain characters were a few levels below the others.
The one other thing I am wondering, is, is it possible to be underleveled to the point where you'll struggle to continue the game? Ie you get to a mandatory story fight and can't win, but without being able to go earlier in the calendar you can't fix it?