I think that we can add to what Gen Whitehead writes that an overrun should also always be allowed in column.
Apart from it, I Believe that it is more a question of not being able to walk 12 hexes on a road before attacking than just column melee.
But I also believe that the target should be taken into considération :
Imagine à 999-strong regiment walking on a road in a forest and bumping into the rear of an unattended lone gun or a depleted regiment with 10 privates left. Less than a minute would be necessary for the leading company to capture the target, with the company at the not even knowing the reason why their march is shortly halted. I see no reason in this case for a change of formation to line...
Therefore, I Will not argue if you attack me in column John
