Well the problem is sometimes you need to try something before you know that it doesn't work. Maybe you can weave 3 dps spells before healing the tanks, but if you never try to weave 4 spells and let the tank die, you never know that 3 is your limit. Not to mention that after the cleric stance changes they can now weave off gcd heals between their gcd dps spells so it's a lot easier to react.

Also clemency in a big pull can actually be a good thing, you lose a holy spirit (around 440 potency with requiescat and shield oath) or a total eclipse (around 120 potency per target with fof and shield oath), gravity or holy would beat those two. Idk how sch aoe fares though, haven't checked their dps rotation.