I just want to correct a point you made, zama will never be at +1 when you are in against lando because of intimidate. This makes the calc look like this
252+ Atk Zamazenta-Crowned Behemoth Bash vs. 252 HP / 112+ Def Landorus-Therian: 159-187 (41.6 - 48.9%) -- guaranteed 3HKO, lando usually...