Sacrosanct
Legend
This is a great mechanical description, but I have yet to hear a story-first description of a warlord character. What characters from fiction (books, movies, comics, radio drama, mythology, etc.) could plausibly be called a "warlord" but not a "fighter" or "barbarian" or "paladin" or some other existing class?
Just my opinion of course, but the only "story" validation I would need is if it fits the story of that particular game table that wants it. D&D isn't very good at reflecting fictional characters completely. The Gray Mouser, Elric, etc? What clear class are they? You kinda just go with what seems to work the best.
So while I see where you're coming from, I don't think we really need a story justification on whether or not the class should exist. Things like "can you create what you want with existing classes/subclasses/feats" are more legitimate reasons as to why there should or shouldn't be a warlord class IMO. YMMV of course.