P is what most people would consider 10x engineer (but not this article). Can get anything done few times quicker than anyone else. It's like 10 junior engineers stacked in one person. But it often would be unmaintainable mess.
M is a lot like article describes. Understands what needs to be done and creates good technical designs. Often unf*s mess created by P. Delivers business value. Do not write a lot of code.
It's funny that depending on whom you ask, M or P would be the 10x engineer and other would be the bad engineer. Real 10x engineer can wear the M or P hat depending on circumstances.