If WARs are getting a boost to their mitigation, I only think it's fair that PLD get a boost to AoE tanking capability. Increase enmity gained from flash by 200-300% and introduce a new ability called "Hold the Line". For it's 20 second duration, block all attacks and take half damage from everything. You're rooted in place and you can't attack, so before popping this ability, make sure you have good aggro.

And since we're blurring the line between PLD and WAR, let's just merge the two jobs into a Warridin. Yeah! A job that has excellent AoE threat ability plus the best mitigation in the game. I'd play that.