Examples of using "разумен»" in a sentence and their english translations:
His argument is rational.
- Be reasonable.
- Be sensible.
He's rational.
He knows better than to marry her.
He knew better than to tell the story to her.
"Treat others as you would like to be treated" should be accompanied with the corollary "Be reasonable."
Admittedly your plan makes sense, but I still think it will be very hard to carry out.