Are you using charged up + blessed ground? In packs it will proc rally (charged up hits proc.
Proc coefficients on Dot Runes is like .033 which is why even with charged up it procs are low in single target instances) and when you stack it with FoTH Divine Well it gets crazy, to the point that you can spam impactful bombardments/every other cool down skill (blessed ground + provoke charged up = effective cool down while Akarat's Champion is up. The three have good synergy).
If you mean by itself then yeah it sucks, but if you are using Heavens Fury Blessed Ground (or any of the DoT runes) without provoke charged up then you are dong it wrong imo (if you are going to consider synergy then you need to include the whole kit).
Slap blessed ground with charged up, Akarat up and dive into elite packs as bombardments and condemns fly. you also gain the benefit of provoke spam which will give you near infiinite wrath (if you have the 4 piece set bonus. I still run into wrath spam issues as I only have 1 piece of the set still).
The only issue I run into is single target takes longer since it procs less, but I now take stuff like bowmen (whose idea was it at bliz to not have these proc rally. It wouldn't be broken at all if they did and is the only issue I have with this rune on Phalanx. Especially when you consider that shield bearers do proc rally with charged up active) and impactful bombardment to counter that issue. Also keep in mind that the original question was about the shield Eberli Charo. There's no particular reason to use it unless you're not using rally but still want to use non-FoH runes.
As far as a Blessed Shield build, i'm still looking for the weapon and shield. Build looks amazing if you do not have the sader set.