Not only is AC being buffed, but lightsmith has a talent that makes your crusader strike do double damage after using a hopo spender. 3 casts of this buffed up crusader strike (with my current stats at 515 ilvl) is a little over a million healing with the new AC scaling and buffed up crusader strike. And in the time it takes you to cast two infusion buffed holy lights (which do 150% healing in TWW instead of generating more hopo), which comes out at ~900k healing, you get almost 4 casts of crusader strike. After those two casts, you do way more healing in a short amount of time.
The caster build may have more sustained healing, but I don’t have beta access os haven’t tested it. Just crunching numbers on what I can.
And it’s not like I have zero healing outside of AC.