I'm sorry but what exactly is the conclusion you're trying to draw here?
Your 1st point states about WHMs healing prowess being so powerful so that we can go for a 2-1-5 party composition (which I personally will love).
Then you subsequently list out the factors that we all know keeps the 2-1-5 party composition from becoming a reality (which makes me sad).

I enjoy reading your opinions, I'm just curious if this particular piece leads to anywhere, or it is just an observation.