I've suggested this before. Formation options:


As I mentioned before, when units are placed, the game will try to overlay the formation onto the map as best it can, shifting individual units that would otherwise be placed in impassable squares to the nearest 'legal' square, which would of course disrupt the formation a bit, as it should.
This way, each side/player does not manually place each individual unit onto the battlefield before combat (preplacement), something that Brad doesn't like. Instead, this would happen in the background, based on your formation choice, with the game AI shoehorning your formation into your starting location as best it can.
This would be a significant change, hence it might be good for an expansion of some sort.
Even without the formation options, it'd still be nice to be able to manually shuffle units in your stack, to influence their placement on the map. My suggestion is that oval 1 should be towards the back/furthest from the enemy, and oval 9 towards the front/nearest the enemy of the available placement squares on any given map, although the opposite order might also work (1 closest/9 furthest).
Now that I have a better understanding of how map placement is determined (thanks to the map builder utility), essentially, you would designate 15 placement squares on the map, with each formation choosing 9 of those 15 squares for placement. Example:
1 2 3 4 5
6 7 8 9 10
11 12 13 14 15
These are all of the available placement squares.
The Wedge places units 1-9 as follows: 13 - 8 - 12 - 14 - 7 - 9 - 3 - 11 - 15
Reverse Wedge places units 1-9 as follows: 13 - 8 - 7 - 9 - 3 - 2 - 4 - 1 - 5.
And so forth... any sides that exceed 9 starting units for whatever reason (i.e. cities) would fill out the remaining 6 squares, or perhaps designate different squares for the city defenders.
So map makers would choose the 15 starting squares for each side, and the formation picker would place the formations into the designated 9 (or less) squares. Each map could have several variants with different starting locations, so as to keep players on their toes a bit.
BTW, I decided after I made graphic # 1 that the Line Abreast formation wasn't practical, hence my not including it in the second graphic above.