In any order approving a proposal subject to an election for an annexation or a reorganization that includes annexation of inhabited territory to a city when the assessed value of land within that territory proposed to be annexed equals one-half, or more, of that within the city, as shown by the last equalized assessment rolls, or the number of registered voters of the territory equals one-half, or more, of the number of registered voters within the city, as shown by the county register of voters, the commission shall require that an election called upon the question of confirming the annexation or reorganization shall also be called, held, and conducted within the territory of the city to which territory is proposed to be annexed.