Honestly they should get their own enmity transfer abilities like THF does.
Anyhow, it's extremely dishonestly to talk about hate cap without also talking about the DIFFERENT hate caps. There are two hate metrics that are added together to determine who has enmity. CE is the hate you get from damage and caps at 10000, it's ridiculously easy to cap and only goes down when you take damage. VE is the hate generated by abilities like provoke and some spells. VE has the same cap as CE but goes down at a rate of 60 units per second. Since every can cap CE easily, VE should be where tanking is focused on. PLD should get a job trait that lowers VE decay rate along with a set of abilities that give periodic VE generation in excess of the decay rate.