Ancestral Guidance vs. Healing Tide Totem
For references I will take this 463 gear profile.
I'll go with the Echo_UF profile, which has a pretty constant damage output with around 17.000 SP.
Heals up to 5 people for 11 seconds and ticks every 2 seconds. Therefore maximum 30 ticks.
Each tick is about 4932+48.4% of SP, which is close to 13,230
13,230x30 is nearly 400,000 in 11 seconds with 3min cooldown.
short term 36,363 HPS; long term 2222 HPS
Heals up to 3 people for 10 seconds for 40% of your damage.
With average of 64k dps this ends up as (64,000x10x0.4)x3 = 256,000x3 = 768,000 healing in 10 seconds with 2min cooldown.
short term 76,800 HPS; long term 6400 HPS
AG comes out clearly on top, even without any consideration of scaling or AoE situations or damage increasing mechanics.
Note that this isn't 100% correct, as a part of our damage comes from pets/totems etc, so it may not be copied.