That really would be too many troops. The map would have to be massive, and therefore take ages to examine. It would just be impractical.

Until the Somme in 1916...
Just so people get an idea of the scale of the Somme... on the first day, there were 60,000 British casualties, and over the entire offensive, there were 1.2 million casualties on both sides. All for seven miles of mud.