Then that's a personal not a "technical" definition and could still reasonably include artillery especially if in counter battery range.
Because of the losses at Hurtgen Forrest and other battles, the US stripped a lot of non combat personnel from their assignments and made them infantry. My late father in law was one-his initial job was a C-47 mechanic and they handed him a rifle as an infantry man and sent him to the war from the states.
The Luftwaffe, after a couple of successes during the 1941/42 where improvised forces of LW personnel managed to repulse Soviet attacks, formed a number of infantry divisions that were an abysmal failure due to lack of equipment and trained officers and NCOs, but those were really second rate infantry, On the other hand WW2 has plenty of "non combat units" involved in infantry combat when dealing with a breakthrough or a raid.
interesting point here.....I would think a unit made up mostly of men inexperienced at infantry tactics, wouldn't do well--as well as non-experienced infantry<>[ Kasserine ]....did the non-infantry units that did well have a lot of time in the combat area and/or beefed up with other combat experienced units??..in the Bulge breakthrough, I thought the combat engineers mailnly blew up bridges/set up roadlocks/etc....as with Giles, he blew up the bridge that Peiper was so dang hacked off about....they didn't have the anti-tank weaponry to hold off a determined main attack....I do read about LW units put in as infantry ''alot'' ...
I'd always assumed that the Red Army and all of it's major components even down to penal units were made up of individuals from all over the USSR and not just Russia. Am I wrong?
What do you mean by not just Russia? do you mean other countries that had already been annexed into the USSR such as Kazakhstan for example?
Russia was just one of the Soviet "Republics". The USSR included the Ukraine, Belorussia, Georgia, etc. To refer to the USSR as Russia is roughly the equivalant of refering to Germany as Prussia or the US as New York.
I guess referring to Russia as the USSR is a common misconception. But to answer your question I do believe that the penal units were comprised of men from different republics of the USSR usually they were criminals of the state.