I went to one of the Dragon Raids while they waited for a Sandstorm and one of Paladins gave me all his gear and they gave me shaman buffs and enchanter buffs. Iirc, his haste item was 23%, Enchanter haste at 55%, and an additional 20% from the stacks of self haste. I'm actually not even sure all that shit stacks, but it "felt" like it did, lol. Never mind the extra 20 in all melee stats etc.
By no means am I saying that with level 60 buffs and raid/end game gear on, that that is a fair comparison to make. But Gahhhhh'fuckin'lee did I just melt the Crocodiles in GF. With lvl 60 clarity on, wisdom buff, etc. - not only did my god procs just fucking dunk (when they did have a good roll) but I'm almost positive that you end up proccing Wrath and Piety more often with more attacks. I've heard people SAY that they dont think combat is related, but it sure as fuck felt like it when I was playing "Battle Cleric, rarrr!" I never even got close to 70% mana (or lower) unless I just non-stop nuked - and this is while I was healing myself through the damage.
Now Im NOT saying that this is a viable format to play at max level. Cause everyone and their mom has this opinion that "Well you're not going to be able to do that later on in the game." "You'll always be out of mana if you're always attacking." "You have to sit all the time." .... I just cant help but wonder if well.. thats because all the high level clerics are geared with the old playstyle in mind. The very clear examples Ive seen of people trying it in stream, the Clerics arent equipped like a paladin. .. They could very well be right, though. Im not saying theyre wrong by any means - but it does leave an air of curiosity about the "potential".