As you mention, skills like stampede won't work. This is basically because the missiles responsible for the damage are spawned before windform. Which is not the case for skills like fortress. So if you want to take the skill-combo route, its important to find skills that regularly spawn new missiles, or spawn them after a delay. SoR is mechanically a smaller barrage, that's why it works. Also, states which spawn missiles, like thundergod, would also work, but 15 seconds or whatever is just not good enough
What about hawk talons? it has 3/2 wdm, and missiles are spawned after monsters walk over the trap. Although I'm not sure how this would play out in high density areas. Could be playstyle similar to ww-sin, prebuff small field and then lure monsters to walk over it. Not sure it would work but sounds fun. OHMAN would work to some extent too.
Some oskill/procs that come to my mind with high dmg and mechanics that would work (not sure if obtainable): phalanx, broadside, hammertime (3/2). Time strike / wave wouldn't work, unless they get procced while using windform. 5/4 skills that would work: barrage, parasite, patriot sentry (not 100% sure). There's also two oskills with 5/4 wdm, danse macabre and harvest, but I don't know what they do.
Other than that, I would say maybe diff approach, proc based, dunno. Haven't played for a lot. Hope this is helpful.