I game AWI using BP. My continental units are a standard 4 bases (45mm x 40mm) of 6 i.e. 24 figures. For skirmishers I have taken it as a standard unit is 12 figures spread over the same frontage?
I feel it more historically accurate to use my skirmishers in small units i.e. in 6s. They are based individually and it is easy to fall into the trap of spreading them out to much across a standard unit frontage of 180mm. I was thinking of basing 3 figures on 2 bases of 45mm x 40mm to avoid this or does it matter if you spread your skirmishers out?

