Look, let's face it, Warlord as a name is just a non-starter. Far too entrenched opposition. So, I'm more than willing to compromise on the name if that means that I actually GET any development on the class - UA or whatever. March/Mark works and is sufficiently esoteric that it doesn't trigger edition warring. Not seeing the problem.
Yeah, there's Hipparch, as well as Polemarch and a bunch of others. At least, that's what turned up in my wikipedia search. It gets the job done, and, once defined by D&D, gets to fall in line with things like paladin (which are only tenuously related to the real life peer of Charlemagne) or druid (with virtually no relationship whatsoever to the real life druids) or any other class name which is largely defined within the game rather than by its real life counterpart.