Don,
Ofcourse, the game sets limits upon us so we have to work within these.
The picture is not visible (error), but if it is the first one that shows up in a google search for Fiat 621 then it would show a city parade and it was not uncommon to squeeze as many troops as possible into available vehicles during such. The photo i was refering to shows several trucks during rural road movement.
Btw here is a fieldphoto:
On dates, first motorised formation (10th Cavalry Bde) were raised in march 1937, vehicles arrived in may/june, initially borrowed from other formations, training started during the summer.