
Actually, Dragoon gear prior to 50 is somewhere between tanking classes and monks (no idea how it gets in endgame because I'm a silly non-endgamer). There are quite a few armors that have the "PLD WAR DRG" restriction, but Paladins and Warriors can always get their own unshared gear that has more protection. I think the only times they absolutely share equipment are at the beginning of the game and at level 27, where the most protective non-dungeon armor is scale armor that can be used by lancers but not pugilists or bards.