As a minor footnote to the agro post above, there are situations where you would replace Tomahawk with Flash. Not story mode Garuda though.

Notice that Flash has a higher agro value than Tomahawk and Heavy Swing. And doesn't require you to target. So if you know adds are going to be spawning in middle of a fight, you can get in position and go like:
- Flash
- target add
- enmity combo

This way you get a larger initial enmity bump to put you over whatever heal is being cast at the time. And you save a tiny fraction of a second on targeting.