Sometimes, when you apply real-world numbers, a single forcing function overwhelms any other subtleties in the analysis. The analysis in this case fails to address the extraordinarily high cost of nagging John must endure when Marsha is inconvenienced N(J) as opposed to the other way around. Since N(J) = K * N(M), and K is never less than 50 IMO, strategy M will be the winner. Always.