I’ve tested this, so there is no evidence that could convince me of that. Alani can single target heal for more than Ambra under 2 conditions: 1) she doesn’t heal a mob by accident (which happens a lot) 2) she has enemies to attack constantly.
But for multi-target healing, Sunspots outheal Alani with the HoT. If we’re being conservative, standing in 2 Sunspots from a level 9 Ambra heals for about 100 HP/second. That’s very conservative since you don’t maximize healing per second by standing in it, but rather by walking into it, getting the HoT, and walking out… the HP/second is much higher if you do it that way.
Nevertheless, Alani heals for a theoretical maximum of 238 HP/second healing from Wellspring at the same level (9), assuming she does nothing other than attack enemies and Wellspring as soon as she gets 3 stacks. So comparing Alani’s maximum throughput to a conservative Ambra throughput, they’re about even when Ambra heals 2 targets and Ambra easily wins when healing at least 3 targets.
In practice, Ambra has it easier. When you’re forced to retreat or simply don’t have anything to attack, Ambra can drop Sunspots and continue healing, no problem. Alani is reduced to the gimped minimum heal from Wellspring and whatever healing options she chose from the Helix.
So the claim that Alani outheals Ambra a hundred fold is just flat out wrong. Math doesn’t lie. Under ideal circumstances for Alani, she can heal for about twice as much as Ambra. In any scenario with no enemies to hit, Ambra outheals her by up to maybe 5-6 times.