I personally have a Tanking set and DPS set of gear. And I usually keep up in damage with MNKs and DRGs in full DL+Relic. In my FC, I went to Titan Hard as my WAR in my DPS gear and we did fine. Plus if an OH SHIT! moment happens with the MT you can quickly grab the aggro and hold off until the MT can be raised and reclaim the aggro.

Just my 2 cents.