The way I understand the matter of the manner by which one speaks English, it seems that people really believe that they can make up the rules all according to their whim, which is based on a lack of their understanding "the logic of language (grammar). Thusly, in the matter of the use of the noun, "troop" instead of "trooper", it is just plain, BAD GRAMMAR, made to be correct by a mass of people that do not understand collective nouns and the logic behind them.
Also, why do MOST people misconstrue the pronoun, EVERYONE, and believe that it is a plural pronoun, as in the sentence: EVERYONE DID "THEIR" BEST TO RECTIFY THE MATTER? The possessive pronoun object of "everyone" is "his/her", NOT "their", which is a plural possessive pronoun! The pronoun, "everyone" is a singular pronoun that takes the singluar possessive pronoun object, "his/her", not the plural, "their"! Any grammarians have a comment to make about this? Frank