Crews

In my rules system, artillery must have a crew equal in number to one soldier for every 10mm of barrel diameter.

So a 37mm gun requires a 3 man crew.  I round down.

A 50mm gun requires a 5 man crew.

The crew includes any troops on the horses, in the vehicle, on the limber.

So this 122mm gun needs a 12 man crew.

Obviously some of them are with the horses and limbers.