There are a lot of trolls using DF just because it's easy to troll. In the case of Titan though, it's highly unlikely you'll win a Duty Finder group simply because of the setup it gives. The second tank is a waste of space to be honest and would be much better suited as a healer or DPS which is why a lot of people just join to troll. You should be looking to make your own groups for Titan, although I'm not saying it's impossible with DF but you'll find it a lot harder. The fight really starts after the heart phase.