Are vehicles towing trailers counted as one or two vehicles for lance/point composition purposes?
I count them separately -Cargo doesn't really count. Unless the towing vehicle is part of the artillery unit that its towing, I consider it independent.
Non-integrated: Four vehicles to a lance, four vehicles towing an artillery battery is still one lance. Unlimbered: One vehicle lance and one battery.
Integrated: Four artillery pieces make a battery, the four vehicles used to tow them are part of the battery. Unlimbered: Battery with vehicles.