Noticed I didn't get several important aas autogranted after lvl96, including combat stability on my SK, and some dps aas on my zeroes including decap. I just assumed we would get all these to 100 so I didn't check. After buying them,changing to dex augs, and not chain casting taps under mc, I'm having zero issues with 4-5 even con now while using 2-handed, and my zerkers nearly doubled in dps, thanks for the advice.
Biggest thing to understand about leech healing (and in turn swarming) is that your healing is a direct reflection of damage done... IE the more damage you do, the more you heal. MC alone doesn't add any damage... it gives a small AC boost coupled with large% leech. For best results, combine Leech (epic2.0 or MC) with Visage of Death. Also, if you have leech going and start getting low, you can hit Lacerating blade for a big heal (big dmg hits) and Dicho is an large insta-cast tap also. Another thing you can do is click shield flash right as your mob train is about to hit you.. giving you 1 tick of safety net to ensure you get your other abilities off and are positioned correctly to deal with your pull.