Paladin actually had Raise previously via cross-class; you just couldn't use it while fighting so you could just as easily switch jobs to WHM to cast it.

Hallowed Ground is not OP because it only lasts 10 seconds and has a long cooldown. Clemency is more OP than Hallowed Ground ever will be, because you can survive indefinitely with it to the point of soloing expert dungeons (but my experiences of this have been when I greatly exceed the average item level).