But the system was far from perfect, you had the M3 Medium Tank, the M3 Light tank and the M3 submachine gun as well as the M3 90mm gun.
The system made perfect sense to the folks involved in development and supply. To them it was not an M3 light tank, it was a light tank, M3. A light tank was clearly a different thing from a medium tank, so who could possibly confuse the two? The question was then WHICH light tank? Well, the light tank M3, silly boy!
The system was adopted in the 1930s to replace the M number by model year of adoption, which was used up to that point.
By 1942/43 almost every weapon system in development since the early 1930s had gone through 2 or 3 major changes.
The whole system proved VERY difficult once the army was in combat in North Africa. Soldiers in battle areas with questionable connections to the supporting REMFs tend to communicate in very brief form. Once the army got on the ground in Tunisia they were confronted by the problem of understanding their own communications…
If a message came in with an urgent requirement to "provide support from M3s", there was no way to understand what was meant.
In 1942/43 "M3" could be a light tank, a medium tank, a halftrack APC, a halftrack-mounted tank destroyer, a 37mm AT gun used by the infantry, a 75mm gun mounted in the new medium tank M4, a new sub-machine gun provided for crew self-defense in the medium or light tanks, a 90mm gun defending the supply dumps with all the other M3 things, or the can opener used to open the ration packs.
And "supporting fire from an M1" could mean a Thompson SMG, Garand rifle, carbine, 57mm AT gun or 105mm howitzer. Oh and the howitzer, 105mm, M1 was on the gun carriage, 105mm howitzer, M2, not to be confused with the howitzer, 105mm, M2 (which was not yet available in theater).
And if you didn't know, the gun, motor carriage, 37mm, M6 used the gun, 37mm, M5. Don't confuse that with the gun, 37mm, M6 used in the light tank, 37mm, M5. Or with the gun shield, M5 used the gun, motor carriage, 75mm, M3.
But it all made sense on paper, I'm sure.
-Mark
(aka: Mk 1)