ok, senario. your a paratrooper. you got shot down. your stuck behind enemy lines. you lost your equipment in the drop becuse you had to cut your strap out of a tree. you see a dead german solgier with an mp40 with, lets say, 150 rounds.(work with me here). you continue ahead, you come up on a dead alied soliger(god bless). he has a thompson with 500 rounds.(the ammo might be unrealistic amounts). now, you may say stait up "the thompson", becuse it has more ammo, and more firepower. now wait, that would be heavy as hell, and you need to run your ass out of there. the mp40 ammo you can find anywhere, dead co's mostly. the mp40 is also slightly quieter. but again, in this situation, you might wanna keep a low profile and not want to kill any1 unless you have to. that means mp40 ammo would be scarse. chose wisely my friend, your life depends on it...
I chose Thompson. I would go with the low profile option. I Wouldn't want to atrract attention, so MP ammo would be scare. This is probaly what most 'troopersor squad with them, then they would go with the Mp40 option, killl many and get lot's. It reminds me of this game I was playing. I had my thompson with 298 ammo, and A Mp40m with 36. I only had one guy with me, And he died soon. I picked up his gun, and got 98 rounds from it. I kept A low profile, and lived. In another, I had 15 men with me. I picked up a MP40, and later had 336, and I started with 46! This kinda shows what paratroopers would do.