There's a pretty big gap in difficulty to me for mages and warriors. Used to be mages had it best. But the sword and board warrior's added defense ability combined with a taunt ability early on is just superior. Barrier in comparison is super weak, and it dwindles as time elapses, while the warrior's armor ability does not. Difference is the mage can apply it to multiple team members, but unfortunately it works as an area effect, so you can only give it to who you can hit. So you'd have to order them to a spot to get the whole team.