I agree with OP about the objective of PLD's design.

If you ask me, I have my image of PLD and WAR like this:

Paladin (knight) - Tankers that have several skills/spells that can protect their allies and have great damage reduction.

Warrior - Mighty tankers that have strong body that can endure a lot of damage (which mean having a lot of hp) and can weaken foes that surrounding them (Provoke to reduce AP) and WARs have nothing to do with protecting allies, just fight by themselves.