These rules are for 6mm and 10mm in 1:1 and 1:2, in one battle you could do it at 1:1 in another 1:2.
Now this means that units are BIG, Mexican battalion seem to have been under strength but still almost 300 soldiers, the rules will also blend big battle with skirmish battle.
I personaly hope to do the battle of the alamo in 1:1

Take a look if you want.
http://www.scribd.com/doc/38142600/Republic-I-Like-the-Sound-of-That