House Rule marching single/double file

[Burt Hoovis]

My friend and I were discussing keeping a unit of infantry in coherency while marching in single or double file. Then when you want to get them back into a firing line your front guys basically have to stand still while your back guys fan out. I proposed that we make a rule that you can choose to (make up a word, "deploy") and move your unit 4" but then fanning the back models out to keep coherency,but also have them in a position suitable for combat.
Certainly not a black and white rule, but I feel like it lies within the spirit of the game and increases the playability of infantry units.

Anyone do something similar to this, or have any thoughts?

[Ponen19]

The 3/3.5 IG Codex (IIRC) had a similar rule where the position of the squad gave certain bonuses, it was essentially the original incarnation of todays orders. Not sure if thats the answer your looking for but it might be worth a shot to look at and see how they worked.

[Soap]

I like the idea of this, but I don't think a rule like this would work in a normal 40k game as it us essentially a skirmish battle where units are in a fight. Maybe a scenario or mission would justify this sort of movement. But even then, each troop can move 6" so you would be able to organise your troops to get into line formation in one... Maybe two turns anyway.