Beat Of A Different Drummer

Hey I get it now. Walking to the beat of a different drummer and where it came from originally. Back in them olden days, before King Arthur even, people moving to new lands traveled in groups, and became known as merchants as they bought and sold items on their travels, of all sizes. Being that a lot of places they traveled through were hostel areas, Kings and Castles, land Barons, Pirates and thieves and the like, these groups would get together and grow quite large. The most successful ones grew to such large numbers of all kinds with smaller groups banding with other small groups that became large. They were small armies as most men carried their own weaponry and they mobilised as one mass. Often these large groups would break up into smaller groups as they moved out in mass. Departing together but separate like platoons. At the end of each group was a large drum and the drummer would set the pace by his beat. If the leader needed the group to hasten up he instructed the drummer to pound more rapidly and if they were moving to fast he would instruct the drummer to pound slower. So each group had it's own drummer and if one group for some reason moved ahead of the group in front them or pulled back and let the group behind pass them it was done to the beat of the drum.
So there it is, he marches to the beat of a different drummer, would be said by onlookers watching them pass and seeing the slower group bringing up the rear or versa vice.