Ok so, Clerics. Clerics have less utility than Wizards, and do less damage. The reason they have less utility and deal damage is because they have better defenses (slightly more hit points, better AC without investment). Of course, to use the utility and damage they do have requires them to be in melee range, where, presumably, they're going to be targeted more, especially by enemies who recognize that they have the ability to heal.
I don't know, I think at that point, "better defense" feels kind of zero sum, since you only have to have it because it was decided that Clerics shouldn't have much range on their spells.
The real reason to make Cleric damage and utility options weaker than the Wizard's is because otherwise, you'd be using them and not being the party healbot, lol. It sounds like backhanded niche reinforcement to me.