A lot of the people who are achieving high threat/dps are swapping in different gear for the fight. It doesn't look like you are doing anything wrong , just other people are hitting harder than you.
As i'm not sure on which threat calculator you're using I'll just use my last PW WWS and mine is no means the best just I know what I was wearing.
Edit - we were both using the same weapon for this.
http://wowwebstats.com/lsotzt4mtivii?s=227128-270706&a=x22277b0
You:
DPS - 2497
Avg Shield of Righteousness - 3486
Avg Hammer of the Righteous - 2141
DTPS - 5160
Avg hit - 9630
Me:
DPS - 3293
Avg Shield of Righteousness - 4270
Avg Hammer of the Righteous - 2779
DTPS - 4951
Avg hit - 8413
Both of our gear looks to be around the same quality, I swop a few pieces around for patchwerk items with +str and +BV mainly as he doesn't hit hard and they provide mitigation. My DTPS isn't that high and average hit low so I'm not sacrificing much by doing so.
When looking at your gear you don't need to wear your +sta trinket for him and can be swapped out for something else.
In short you're not doing anything wrong just those that are higher than you are wearing more threat/damage pieces, which for Patchwerk isn't a bad thing to do.
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