The four Brigades of [First] Corps had been very much mixed up together when occupying the Villages during the night, which will account in some measure for the promiscuous manner in which their several Battalions appear to have been distributed during the battle.
--William Siborne p. 201Breakdown of locations of battalions per Siborne (the only source I've found that really goes into this level of depth). The brigades of 2nd Corps (on or near the road to Sombref) are deployed in "classic" deployment of "three lines of columns of battalions at deploying intervals".
Also note 4th Brigade is short the 13th Regiment which is garrisoning Mainz (corroborated by Mont St-Jean--link at right). 1st, 3rd, and 4th brigades are all accounted for. I/6th Line from 2nd Brigade's disposition is left out of Siborne's account. For the battalions defending/garrisoning the villages I just placed column markers.
The battalions and dispositions of 1st Corps are very mixed. Jagow's 3rd Brigade is employed in both St. Amand and Ligny and this explains the confusion of various maps listing Jagow's command in either location depending on the time.
For easier viewing the full size map of the battalion deployments is available here: http://www.mediafire.com/download.php?3t2umn7ilyk4lih
This second map helps illustrate better at a glance the "promiscuous" dispositions.
Stay tuned next week, same lead-saturated-time, same lead-saturated-channel for Mapping Ligny: Opening Assault!