bro not even doing that bad, first thing i always check is gear though, the only "bad" thing i notice is the gems, which is incredibly minor but as far as i know, having a mainstat gem with all 4 gem types is just better, the 0.15% crit effect is the obvious choice, the movement speed gem isnt bad either for uptime. This is very small though.
a possible bigger thing is you have unbridled ferocity talented in your latest vexie kill which makes me believe you are running that on every ST boss in the encounter, its better to have 2/2 in deft experience.
gallywix is your worst parse though so ill go over that, you kill the boss before phase 3 so you automatically are already at a disadvantage because you dont get to pad on those, ill link a picture which shows you and another warrior (top 10 log) he has the exact same cooldown usage and peaks at the same time you do, also almost identical kill time, however he does way more damage than you.
The first thing is he has short troar talents, and gets 100 million more damage from troar than you do, which is the only talent difference and while it does matter, there is a bigger problem here and its cooldown usage, in the picture i linked below he has 2 spots where he peaks way higher than you do (circled in red), its caused ENTIRELY by what vezna (other warrior in the log) does earlier in the fight, he saves his 4th reck for almost a full minute so he can pad harder on the adds, where as you send it instantly, but since he saved his, he ends up getting to have reck on a fat ass add stack where as you dont and suffer greatly because of it (second red circle)