You can't really get to level 34 through those. Those are end game activities that pretty much need you to be 33 or 34. Definitely don't waste your time going into trials if not a level 34, unless you're actually a pro or semi pro halo player...? However, the level 28 poe playlist could be a good idea to replace the strike playlist (when done with all weekly activities, on all 3 30ish characters).