I didn’t tool around with the Seismic Slam version. Whirlwind is not really a good choice for the Might set, tbh - it won’t be doing any damage and is not a fast spender, so won’t be helping reset CD. All you are probably getting out of it, I am guessing, is some healing via Blood Funnel? Better off with Ground Stomp, which is at least boosted by the 6-set and is a generator so you can pop Slam again.
Or switch to Wrath of the Wastes, but I hated that set! ;)