There is no single right answer, but if the co-founders agreed to something, then held their choice against party making a request - that to me is a much more serious issue than the party that make the request for a higher salary.
>if the co-founders agreed to something, then held their choice against party making a request
One can "agree" to something because of business expediency but simultaneously have a human response that it feels unfair.
As analogy, I'm sure many programmers have "agreed" to a low $55k salary and took the job but simultaneously felt that the company was unfairly compensating them because they thought they were worth $100k. Unfortunately, agreement doesn't override human feelings.
If you were interpreting my blurb from the book that the 2 founders were constantly throwing the unequal salary in the 3rd founder's face, I don't think that's what happened. The book made it seem like it was a more like a silent resentment. Also, the salary argument came up after Zendesk was already established and running. I didn't previously make it clear that this wasn't 3 founders deciding on unequal salaries when Zendesk was just an idea on a napkin. If one agrees at the founding, that should remove triggers for resentment.
Signing a contract doesn't switch off emotional reactions. Under duress it is difficult to remain empathetic or to maintain logical distance from disputes.
