I'm wondering specifically how much value the 2AN+MR damage from the death weapons has for your troops. If you just care about your mages giving afflictions, Death 8 could be a cheaper alternative. Also, I'm wonder about cases where a death bless could interfere with fire/frost brand effects on your demonbred thugs.
Is idea is that anything that can't be killed by your resource intensive capital-only sacreds will at least have afflictions? The downside is that your sacreds will also be dead and they are hard to mass. I'm a little skeptical, but I suppose it could have situational uses.
Which battlefield spells really benefit from an affliction bonus? Fire storm and a death bless on the other hand may be handy, but in most situations, I'd rather have the enemy dead rather than afflicted. It seems like the purpose of low and mid level evocations spells is either to kill the enemy or not. Maybe Heat from Hell is another candidate, but if you get to the point where fatigue is doing damage, they are probably all dead anyway... If you are struggling to kill the enemy this way, I think you may already be in trouble...
Maybe it depends on what you're fighting though. If you're dealing with giants, SC, or hydras afflictions could useful. When dealing with chaff, probably not as much.
Personally, I am not sure about the value taking blesses with Abysia. Good scales and a decent awake pretender for early expansion are probably more optimal, since their basic troops are powerful as is. My main concern of course is the question of what is most optimal.