We know that the game decides by itself which character will be the real governor in a city. It ignores PT's, and other beneficial traits and enforces a character you might now want. Usually this is not a problem, since you can barely have more characters than cities, but in the capital, where your best university is for Admins and in a Citadel for the militaries, this can be a problem. Usually these 14 y.o. noobs rarely have better traits than the governor, but this can happen. You lose some income and ofc the population drops. It is a bit annoying, and I hope there can be a way to chose who will be the governor of a city among several generals in there simultaneously. The effects are not that important, but if your fortress is at 29k pop and it has a +0.5% growth, and the new governor sets it at -1.5%, oh well, this is really a set off.