So just something I noticed right off the bat, you are SMF, but you are using the stat priorities for TG. Changing gems out of crit and into more strength will help a bit, though not 15k worth.
The reason for this is that as SMF you are going to be hitting almost twice as often as you would if you were using TG, making the odds of you getting a crit higher as SMF over any amount of time. Crits cause you to be enraged, which then causes you to do 10% more damage. The problem is that you don't hit for nearly as much damage as you would if you were TG, so strength adds the extra punch there. When you are going TG, you are already hitting f'n hard with two 2-handers, but bad luck can cause you not to get a crit for a while since you attack much slower. Thus, TG stacks crit to avoid this.
Another easy (but somewhat time-consuming) thing you can do is get either of the strength 463 blue trinkets from heroics; either Carbonic Carbuncle or Lessons of the Darkmaster. Despite their lower ilvl, their functions and stats are more beneficial to you slightly more than the LFR Final Orders. (again, not going to make a 15k difference, but still an easy fix)
Without a WoL recording both you and this other warrior I can't really say what you are doing right or wrong, but these are just a couple simple things you can fix in the meantime, along with studying fights and timing your cooldowns to maximize damage.
Hunters never die, they just choose to commit suicide. Often.