Most importantly, TEH is only relevant when maximized against a specific sequence of events. If you want to maximize it on Gormok, you're maximizing TEH against melee+impale+bleed tick(+melee, potentially). So you're going to look at your largest bleed tick, your largest impale, and your largest melee hit, add all those together, and figure out how good armor is against your worst-case burst based on the percent that can be mitigated. Anub is significantly more complicated, but the math can still be worked through. Add up the worst-case burst, figure out how much is nature, how much is physical, and how much is something else, and you'll derive TEH values for each stat. And NR will come out pretty well.