Do the Supervisor's Premium Salaries Make Them Poor Union Negotiators?

The OCTA decided to make a balanced comparison of our supervisor's salaries compared to eight other counties. This time we compared to four counties with the taxable valuation closest in size to us on either side....the next four smaller and the next four larger in size. We then averaged the total salaries of the nine counties and found we are spending 36% more for supervisor's total salaries then the average total salaries of the nine counties. See our chart here.

The other eight counties have three supervisors. Other counties with five supervisors often pay significantly less. When our supervisors find it necessary to overpay themselves so much, does it make them less able to negotiate with high-priced unions? Do taxpayers get fleeced all the way around by the excessive pay of the supervisors?