WotW is hard to beat. Are you saying that WotW with a Greatsword feels more powerful than a Devoted/Helwalker with Greatsword? Or are you using two weapons on the SC to optimize the Full Attacks?
There are 2 ways to go with this Brawler that I'm seeing. One is more defensive and stays in the middle of enemies with Mob Stance on and Refreshing Defense, etc. The other plays at range with Dance of Death and Conquerer's Stance (won't stack with Dance, but is +10 Acc for the first 12 seconds until Dance can stack up).
The Mob Stance bruiser version with Firebrand, Accuracy is 119 (109 with Savage Attack on) in Mob Stance self-buffed only. You could pick up +10 from a priest or 5 from paladin/deadeye. *Note that Mob Stance Free Attacks get bonus Accuracy: +8 ability level and +2 per power level (+10 for this character).
As for speed, after a Crit (for necklace buff) with 2 enemies engaged, attack speed is .4 and recovery is 1.9 (1.8 with Abraham). That's with every slot dedicated to speed (Aegor's, Necklace of the Harvest Moon, Helm of the Falcon, etc.).
I'll play around with the Dance of Death + Instruments version, but I think it's wanting something different. There's less incentive to wear the Contender's armor, since we won't be engaging from range and the extra armor isn't helping as much. Someone who is better at attack/recovery math can weigh in if downgrading to Miscreants is better here, or if the single large bonus from Mobility is still better, or if we just scrap light/medium armor + Armored grace and switch to a 0 recovery armor. You would want to dump RES here instead of INT, to extend the duration of Instruments.
Also, in a little bit of testing, I don't think wound generation is high enough with just Voidwheel self damage and Dance of Death. The 4 wounds for Instruments, which needs to be refreshed, along with Thundering Blows, leaves very little for Monk Torment's Reach (which gives another +25% additive DMG). I'm imagining trading out the Devoted for a Berserker would work better. In that case we really are dancing with death. You probably would have enough wounds to keep up Blade Turning, in a pinch, but the self-DMG might be too damn high.