The district government has posted a link where you can calculate what your new tax bill will be for the proposed fire district:
Florida Fire districts quicksearch
I suggest you check it out if you're a disabled veteran or even someone who has a significant save our homes deduction.
Neither of these benefits are applicable for the fire district assessment. Instead, it is based upon the total market value (relative improvement value)
Depending upon the level of disable veteran discount and/or save our homes allowances, property taxes could increase anywhere from 15% to 25%.
I seriously doubt the homes are going to see a similar reduction in their Sumter County taxes when the adjustment is calculated for the new fire district.