https://assets.mozilla.net/annualreport/2018/mozilla-2018-fo...
edit: More broadly, pointing out someone as making a false statement does not mean you agree with the opposite view, simply that you don't like people spreading false statements.
A related point on fungibility turned up in earlier discussions: donating directly to Firefox might not count for much if Mozilla balance it out by redirecting the same sum of their general fund away from Firefox. [0][1]
So as long as the Mozilla mission is not aligned with the "Firefox mission" there is no winning.
Overpaid relative to what? Other CEOs of similar sized non-profits? Do you have evidence to support that claim?