Challenge for the problem composers!

[Richard Pask]

From The Personality of Chess:

Stipulations (Page 190):

1) The problem must consist of a minimum total number of pieces.
2) Each piece in the original setting must be mobile. No blocks allowed.
3) The forces of the two sides must be numerically equal. [No. of kings/men may vary]
4) Now, it must be possible to demonstrate conclusively that if a specified piece of a given side is a king (White, say), White loses; but if that piece is a man, White wins.

The author composed a setting with 4 pieces a side (which I'll show later), and strongly implied that just 3 pieces per side was virtually impossible.

Over to you!