Yea leveling healing units is pretty good to do since well... leveling can be hard if you aren't actively doing it. Once they reclass into something thatcan heal and deal damage they are a lot more potent.
and don't reclass until level 20 (20 is max.level, you can reclass at level 10 onwards) - or you'll loose out on a huge amount of stat-points (since you'd effectively loose 10 levels)