I mentioned BfA and you’re here talking Legion, but sure, I’m the one who can’t read.
Legion Aff was propped up by the overperformance of Reap Souls and our artifact weapon, and this was never made more apparent than in BfA where they had to cobble together Darkglare + Deathbolt to even give the spec a chance to do damage.
If you didn’t have those ready, your target swapping was awful. To make UA stacking work is going to require a lot more changes than just swapping the spender.