It doesn’t go off 400ms later, ALL spells within 200ms batches are processed at the same time.
Is it 400ms or 200ms?
No, it’s not. You should be casting a heal before they’re even low enough to die from one attack. That’s not random; that’s you sucking at your job.
And again, it’s not before they got hit, as far as the server is concerned; it’s as they got hit. You know how spell batching will work, so you shouldn’t be waiting that long to heal.
Rephrasing to mean the same thing doesn’t make you correct. It’s not random, nor is it bad luck.
YOU made the mistake.
Random would be “10% chance for your heal to do nothing.”
Your heal and damage received being processed in the same batch prioritizing damage taken thus killing the target despite your heal going off is NOT random.
There is zero randomness. You can predict when the damage is coming, and if you’re waiting to heal someone until they’re going to die from the next hit, you made a mistake.