The Ifrit level 20 battle can be easily duo'd, the level 34 Titan battle can easily be duo'd or trio'd.
Video of it being duo'd or you are full of crap. "Easily" implies that it is possible for the majority of the game.
No one can both survive and put out enough DPS to kill the heart as a duo.
edit: Referring to Titan.
Actually it's plausible. I tanked Titan without healer and only 1 other DPS, survived for good 5 mins before we died due to Rock/Heart/whatever that was, cause we didn't know we have to kill the Rock/Heart/the heck. Pretty easy to tank as a WAR due to self heal and large pool of Hp. Also since we didn't know bout them Heart/Rock, we just focused on Titan and did put it down to 1% Hp before the screen flash and everything reset. Once we know we had to kill those things, it became pretty easy.
I also tanked through Titan jump by staying till because he could at most took off 30% of my Hp with the jump, and I would always be full health prior (inner beast <3). Well, mostly because I'm terrible at evading that jump.
Like that Garuda Easy mode, we only wiped once because it's first run for 3 out of 4 (at 10% Garuda health as well). Once we know what to do, it became flawless run even with the whateverthingy Garuda did in the middle, we all had more than 50% hp to survive and plenty of rooms to spare. Gotta say, those fights are plenty easier than in 1.0 due to latency made it much harder to evade attacks. It isn't as hard as people made them out to be, or at leas people who played 1.0. Blergh, Ifrit Extreme with latency.