Honestly, put Defiance back on, and just don't use Butchers block if your above 80@ on the Aggro meter. Just remember to use IB every chance it's up, AFTER a heavy Swing, and you will do MORE damage than without Defiance. (This has been tested and parsed by a friend when I had my Bravura)

If you are going for Marauder with cool downs as a supplement, then I would say go for it, and see. I have yet to obtain the Garuda Axe to try this, and I don't want to do it with the Ifrit one.

The Dragoon in your FC was performing VERY poorly, he should be pushing out at least 100 DPS in order to sit on that spot. He is definitely not keeping up all his DOT's, heavy Swing/Disembowel, and Chaos Thrust. If he's not, his gear is bad, or his weapon is bad, or he is bad. =/