I was reading T.A. Heathcote’s, The Indian Army: The Garrison of British Imperial India, 1822-1922 and came across some interesting numbers that will be very helpful in formulating column speed on the tabletop.

Indian Army Transport Characteristics
Description	Speed in MPH	Number per minute passing a given point in single file
Pack-mules and ponies	5	25
Horse- or mule-drawn Carts and wagons	2 1/2	10
Bullock carts	1 1/2	6
Camels	2	10
Pack-bullocks	2	16
Pack-donkeys	1 1/2	12
Coolies	2	30

The amount of road space required by each type of transport, including intervals was roughly as follows:
Pack-animals (or pair) 4 yards
Camel (or pair) 5 yards
2-pony or mule cart 7 yards
4-horsed wagon 15 yards
2-bullock cart 10 yards
4-bullock wagon 20 yards
Gun, limber, and ammo wagon 40 yards
Cavalry, sections of four 4 yards
Infantry, in fours 2 yards