What’s LoE? I know some people don’t like how War Cry feels, which is fair enough. But it’s not like this build has an incredible amount of buttons to press anyhow, and the damage reduction is way too invaluable in SR etc.
If you read my original post, you will see that I am trying to go for a more balanced approach here 
So it is not a pure shield build, and if you look at the GT stats you will see that the chance to block/block recovery are far less than some totally devoted shield builds - say, a Markovian S&B tank. This fact alone makes Anvil less worth it, because you will simply be blocking less. Believe me, I also really wanted moar hammers flying around on screen for the cool factor alone.
I also believe it’s the opposite of a must-have for this build. It’s worthless aside from the proc, which I just explained why will be less useful here, and other devotions taken increase all of our damage full-time.
Edit: Oh you mean Light of Empyrion. Yeah I considered it, but it takes 7 points instead of Vire’s 6 so it didn’t work here. It’s also an option if you move some other stuff around I suppose. I also wanted to try Vire because I had never tried it before (like so many things in this build, it’s kind of an underdog devotion), and turns out it gives a ton of damage+shield stuff so I couldn’t be happier with it.
Last words – I can easily kill all celestials with this setup even as a noob with sloppy gameplay (talking about myself), sooo I would question your word choice in “insufficient” XD