Always surprised by this kind of responses... You don't even need to compare SCH/WHM, you don't need all these maths ; if you feel MP is bad on the WHM you are the issue (or your team mates are). That's all.

Not to add a WHM can dps from time to time in any content. If some are able to dps that's the proof MP is not an issue at all.

Also MP management is the chore of the WHM job... Remove it and the job itseft loose its entire interest, no more challenge, no more fun... WHM is perfect as it is, WHM is WHM, not SCH, don't care if one recover more MP by time they are not working the same.