Hey, my tuppence worth: I like marshal more than warlord but I dislike the connection with horses and (even worse) US marshals -sorry Dr Strangemonkey

To me a marshal is a bloke in charge of the horses (medieval, therefore in DnD era) or John Wayne!
"[Middle English, from Old French mareschal, of Germanic origin.]
marshal·cy, marshal·ship n.
Word History: Hard-riding marshals of the Wild West in pursuit of criminals reemphasize the relationship of the word marshal with horses. The Germanic ancestor of our word marshal is a compound made up of *marhaz, "horse" (related to the source of our word mare), and *skalkaz, "servant," meaning as a whole literally "horse servant," hence "groom." The Frankish descendant of this Germanic word, *marahskalk, came to designate a high royal official and also a high military commandernot surprising given the importance of the horse in medieval warfare. Along with many other Frankish words, *marahskalk was borrowed into Old French by about 800; some centuries later, when the Normans established a French-speaking official class in England, the Old French word came with them. In English, marshal is first recorded in 1218, as a surname (still surviving in the spelling Marshall); its first appearance as a common noun was in 1258, in the sense "high officer of the royal court." The word was also applied to this high royal official's deputies, who were officers of courts of law, and it continued to designate various officials involved with courts of law and law enforcement..."
ps..but I can't think of anything better anyway