We did a run with PLD and WAR in the same party for WP once. Our WAR and BRD raced for DPS on the Tonberry King and other bosses and the BRD got 215 and the WAR 185, Warriors can dish out some pretty great DPS (Although they'll always be behind DPS by a little), but only if you let them DPS :P
We have our Warrior DPS'ing like everyone else and if the PLD goes down, he rushes in to buy us time to get the PLD back up and it works. It's kind of like having a DPS Tank Hybrid which is handy.