I had a few readers tell me they had no troubles as Blood tank heroics, so I went and tested it more thoroughly.
Result is I’ve changed my view, and now think it’s quite viable. I’ve updated this post and include a screenshot with the corpse explosion damage, which is one of the two key things you need for it to work.
Frost or Unholy still beat it hands-down, but Blood doesn’t suck. I even succeeded in Utgarde Pinnacle, which is an ugly gauntlet and corpses despawn mostly before I could explode them.
Also got the Conquest badge helm now, and man I am looking ugly. I’m a mismatch of gear. But, I’ve got 32.8K unbuffed health now, which feels solid.
Aug 19 update: got the chest too, 33.7K HP now.