TF Veng Pala - Not healing enough?

Hi, I've made a TF veng pala and it feels like I don't regen enough.

Is there something people do to increase how much they regen with this build that I should do?

Life on hit ( jewels, chants )

if you get your merc defensive enough, you can just take a prayer merc and equip him the crucible lvl 10 helm. Devils bargains mass regen aura adds like 200 life and regens a bit. Together with prayer from the act2 merc that gives some nice lifereg.

If you want to heal on hit, then the best way is to either go with life on hit or with high physical damage, good AR and good amount of lifeleech. Not sure tho how lifeleech will work with vengeance, since you hit pretty slow and hitting bosses wont get you any leech.

Why not a combo of the two , the merc with the regens auras + enough life per hit to sustain urself, there are also IAS+Life per hit adds jewels so that could work aswell maybe try on the draculs gloves for life tap , would that work for vengeance?