This should upset you.. but you probably already knew.
Dashing Strike is used to proc Rainments does Dashing Strike % affect the proc .. no (not only that its fairly low damage)
SWK -- You could argue that in fact its all spenders synergizing but really its just a way to proc it, even WoL does minimal damage compared to SWK proc + Mantras is the fastest way to cycle, and you cant buff em.
Dh - any spender or sentry for marauders as well as 5 pieces total (most of any class) for skill % buffs that directly affect sentry damage
WD - Jade Haunt/Locust Swarm directly are the center of the build so..
Wiz - check this .. meteor % damage actually affects meteor damage on Tal Rasha's
Bar - EQ affects EQ + they have a passive now that also helps with it and the rune you use EQ on is the same one as lut socks proc.
Crusader - (oh this guy) I mean even if he didnt have many OP things that are copied off monk but 1000x better *cough* Indestructable The main builds are all centered around skills that can obviously be boosted by their own damage % as well as synergizing with Akarats (darklight) or a weapon/shield (Shotgun, condemn)
I mean every argument aside.. how are you going to have meteors be affected on Tal Rasha's but not have Dashing Strike Damage up the Dashing Strike proc'd proc.