When issuing an attack order I know that the game is abstracted to behave as though the Motorized and Mechanized units have dismounted from their vehicles and are advancing on foot.
When issuing a move order, in a formation other than Road Column, i.e. Vee, Line, Successive Line, Arrowhead, are the moving units abstracted as moving mounted, or on foot, or a combination of the two depending on terrain and proximity to enemy forces?
If I am not mistaken, they march in road columns, but switch to the ordered formation when reaching the end point (destination), or the reorg-point (of an attack), as the formation will then be used for the final leg/approach. Motorized units always move with "wheeled" speed, foot units with ... well foot speed. In COTA, wheeled elements of a foot (simulating horse-drawn units as well) unit would do a stop-and-go loop (afaik) to adapt to the speed of the slow units, in order to stay in column formation. That's why I used to detach such elements, to maintain the speed advantage.
Not sure if CO2 features 3 speeds (wheeled, foot and horse-drawn). The Wehrmacht actually used special carriages so that they couldn't just tow guns or transport ammo, food and fuel, but also transport troops with these horse-drawn carriages, on the retreat, or as pick-up at railway stations, for example.
Usually, all troops were re-deployed by railway (medium and long distances), and - when time was essential - non-motorized units picked up by the supply columns (trucks) that were present at the destination (eg. the trucks of a superior or neighbouring unit, or the Army base in that sector), to get them to FUPs, rest areas or devensive positions.
