It’s hard to judge this all without actually trying it, but it’s hard to imagine that this will be fun with the way current paladin plays.
The spec has a ton of issues and layering another system on top will probably not work.
Also what does “Blessed Assurance” even do for holy paladin. We don’t even have Crusader Strike keybound in raids, it is so useless. Unless there is some context we are missing, like Avenging Crusader being somewhat baked in to our spec, then this talent does not make sense.