In the choice of pronouns, simplicity should prevail

The choice of pronouns for an individual is straightforward if the sexual oritentation or preferred pronoun of the individual has been known or declared.  When neither of such are known, however, the question remains Which pronoun to use for that individual?  In the classic The Elements of Style, Strunk and White propose the convention of treating "he," "him" and "his" as the pronoun for a generic individual.  This convention merits on simplicity, which I think is the fundamental reason why pronouns are needed at all, otherwise why not just repeat the likely lengthier noun?  Compared to the opposite alternative of "she," "her" and "hers," the Strunk-White convention saves some keystrokes.  The second alternative, the seemingly neutral "he or she," "him or her" and "his or hers," not only sounds time-consuming but also falls short of its goal of political correctness:  First, it still has to fight an internal battle with "she or he" and "her or him," etc.  Second, and more importantly, the binary view that an individual is either a he or a she ignores the possibility, as the progressive side suggests so often, that he can be any convex combination between "he" and "she."  The third alternative is the dehumanizing, objectifying "it," which I doubt has much a grip.  Finally is the alternative of using "they" as a singular pronoun for a person, such as some journals nowadays requiring authors to use "they" for a singular player in a game-theoretic model.  The confusion in such a context is obvious.  In general, such a "they"-convention would sacrifice information about how many individuals are being referred to.  For instance, when someone says "They saw the police abuse a migrant yesterday," we are no longer sure whether there can be multiple witnesses available to testify against the police.  While some might point to "you" as a precedent for pronouns that make no distinction between singular and plural forms, "You saw the police abuse a migrant yesterday" would not lose as much information, since it is common knowledge between the two sides of the conversation whether "you" - whom the quoted sentence is directed to - means for an individual or a group.