@Brian Van De Walker
Good example. The Tommy gun is bulkier and significantly heavier than a M1 carbine.
I first noticed the weird ratio of SMGs to rifles in the Resistance kit when I tried to make a 500 point Bolt Action list from one Wargames Atlantic Resistance box.
The lack of rifles actually forces you to go one direction in your build.
The truth is the Resistance carried what they could get.
1) They obtained civilian arms floating around. And on the Continent there always has been and probably always will be more long arms (rifles and shotguns) than anything else.
2) They had stocks of French military arms they might be able to acquire. The French Army was almost bereft of SMGs.
3). They captured arms from the Germans. There are only 5 SMGs in the entirety of a German Infantry Platoon (Notionally 52 men, you can call it 40 because real life) to potentially capture. The ratio of SMGs to rifles only gets worse among German rear echelon and garrison troops that the Resistance would have actually targeted. The Resistance would have to wipe out a Company or more worth of Germans to get half the number of SMGs in the Wargames Atlantic Resistance box.
4). Yes they received arms drops. This would have raised the ratio of SMGs but not like we see in the Wargames Atlantic Resistance box.
But what about picture X or Y?
I'm sure at times and places all the SMGs a cell could get were concentrated. Which means a squad of 6 with SMGs is plausible. Thirty some Resistance fighters built from the box with SMGs is not.
Also bare in mind most of the famous Resistance pics are probably post liberation cosplay. Village or city liberated? Time to take some SMG selfies with the passing through GIs for post war street cred.
Moreover, just like many modern GIs grab a SAW or 240L for his Instagram picture, many real Resistance fighters probably grabbed a SMG for their photo.