I’d like to standardise the base size across the units on the game.
Currently this is set to 40mm wide but no specified depth. I’ve been using 40mm X 30mm with two dice holders to show the formation and number of combat dice.

I’m now considering making all bases sizes 40mm square. There are two reasons for this;
1) it will allow players a little more room to make diorama bases.
2) if the player feels inclined, instead of using a die to denote the formation they could make three different base styles up for column, line and square.
The benefit to this is that it would also give the battlefield a more realistic look.