Tank retention alone should warrant serious consideration when looking to Samurai being DPS over Tank. You need Tanks to clear content, to level new jobs, play the game... Not incentivising this (admittedly small) player base would only serve to highlight a problem MMORPG's have had since inception, every body wants the next big thing... Having the players leave DRK, PLD, and WAR to level DPS SAM would have four Samurai in Palace of the dead tripping over landmines or roaming in fate armies to level...

Congratulations, you can now pose epically behind the enemy with your cloth wearing sword DPS while your bird Tanks for you, amazing way to showcase the proud honorable Samurai.