Slotting Logistics provides all units with 1 extra Movement if they start their turns in friendly territory. Both military and civilian units receive the bonus, making this policy useful in both wartime and peacetime.
In the late 16th Century AD, the size of armies in Europe increased dramatically, and forces of 100 thousand were not unheard of (although these reported numbers may have included the horde of camp followers as well). Given the state of transport and roads in the Renaissance, in general when operating in enemy territory an army would forage (i.e., pillage) to maintain itself. But this didn’t supply much that was now necessary – munitions, siege guns, uniforms, medical supplies, booze, and all the other things that keep soldiers content. Thus, the baggage trains that attended armies grew; during the Thirty Years' War for some mercenary armies this amounted to a wagon for every 15 men.