Either the wording in the descript should add, "but not when a unit dies", or it should give Mother Talzin 35% TM ANYTIME a unit falls below 50% health, including death. If the latter is too OP, perhaps Zombie could be the exception?
I mean if an enemy is at 5000, you do 4999 damage, you get rewarded. If you do 1 more damage (5000) and defeat the unit, oh so sorry!??
Personally, I'm ok with NS getting better. The Devs will decide.