Sec. 1. This chapter applies to the following counties:
(1) A county having a population of more than four hundred fifty thousand (450,000) and less than seven hundred thousand (700,000).
(2) A county having a population of more than one hundred eighty-five thousand (185,000) and less than three hundred thousand (300,000) that opts in to the system of county government as described in IC 36-2-2-4(c).
(3) Any other county not having a consolidated city, if both the county executive and the county fiscal body adopt identical ordinances providing for the county to be governed by this chapter beginning on a specified effective date.