Yes, well-gear WHM will have little mana issue. But in a long draw fight they will get low and they cannot spam as much as scholar.

I agree stacking regen is very strong and it is the reason 2 WHM is viable. However, giving scholar instant AoE heal will make 2 scholars very potent as well (because of their pets), might be even stronger than 1 scholar 1 whm (might be). I liek class diversity and I like classes to have strength and weakness.

Are we able to do all the 4 man content perfectly fine?
Are we valuable to 8-man as much as people will prefer 1 scholar/1 whm than 2 whm?

If the answer are both yes, I see no problem in our current position.