A county (or city) pays for things, and they decide to setup a property tax, taxing some arbitrary "assessed" value of your property. It doesn't mean anything to me to say your same income is being taxed twice, thrice, or 4 times. You're just paying for services to n different organizations, in this case, government agencies.
If the taxes are too high, then they simply need to be lowered. But not via deductions or any other game. Let the true prices be easily visible. No one forces a state government to implement a % of income tax, and if it's too high, then voters in that state should demand the the percentage be reduced, or implement a flat amount. Same for federal, same for city.