An artillery unit would be a prime target for the opposing force. Think about it. An artillery unit is big, loud, necessarily out in the open and potentially deadly to anything in its considerable range. Aside from the obvious danger of aircraft, infantry and fast attack vehicles would typically make a beeline for artillery once they figured out where it was. By the Second World War, artillery teams would often use the "shoot and scoot" tactic because of this. Fire off a few rounds, then get the hell away before anybody could retaliate.

Artillery crews were, therefore, issued with weapons although typically there would be fewer and lighter armaments than a regular infantry company. The American M1 Carbine, for example, was specifically developed for artillery crews, logistics teams, engineers and anyone else who wasn't expected to actually be on the front line but might encounter the enemy nonetheless.