Some people need to calm down read what the OP was saying. Here, I'll break it down:

In comparison to A9, A10 & A11 the healing requirements of A12 seem out if step.

Now, the OP did not say that it needed nerfing, or that it was too difficult, just that in comparison to the rest of the new Alexander raids it is unusually tight. Imagine the jump from healing Brayflox to Stone Vigil at their original ilevel - it comes as a shock. It's not particularly difficult to heal SV but if you're expecting an easier time like in Brayflox you've had it. That is what I took from the original post.