I'm about the same level warrior and have same TP issues. I just let my tp regent up a bit if it's low by auto attacking.
A method I've found works is tomahawk the main target while running into the group then run slightly past them, they'll gather behind you allowing you to use an overpower.

Tomahawk is a tp hog I don't know how effective it is just not using it and getting initial aggro by just running into the group.