[ffn]

He doesn't even have to hang out with peers, one simple search across some popular job site nowadays (e.g. glassdoor) will immediately land you with a decent salary amount for your desired position. We've already entered the brave new world where the concept "salary is private information" is dead, and, if one is a developer active on Github (or other OSS platform), then the concept "my work portfolio is private" is also dead.

So you're absolutely right, the worst thing for a hiring manager and a potential employee to do is set themselves up into adversarial positions of who can best manipulate and "break" the other person first. Because a company built with employees and management who can't trust each other, and are in constant underground wars to gouge the most out of each other, is bound to get trounced by competitor companies in the open market