M1921/28 is a very nice gun, but I do like the 50 round M1928A1 too, I have an assaulter squad equipped with them on BR5, they do a good job at cleaning rooms and bunkers.
Anyway using drum Tommy is logical if you are playing BR5, but in terms of power excluding magazin size M1921/28 is much better and having a 100 round on it will probably turn that gun into the best SMG of the game.
MP40 kills in one shot less than PPS at close range - its not inferior in theory, however both need 3 shots in mid range which makes the PPS shine again.
The main problem still is that body armor removes the close range benefit, which makes the PPS then the much better gun.
I like the ZK-383 and use it almost exclusively on my level 3 squads. However, with the Russian PPS42 and PPS43 being over-buffed level 2 smgās (google search says it only really shoots 500-600 rof), they should consider moving the ZK down to level 2. Of course, searching google I find one google search rate the ZK at 500-700 rof and another listing it at 500 rof.
Personally, I wish DF would just take the most accurate data they can find of the real gunās performance instead of over buffing some guns. At least that way people might bitch about a certain guns performance, but they would have to blame the gun manufacturer instead of bitching at DF.
If you value more DPS and performances at range than large mag, you may consider sticking to the BR I 20 rds Beretta M38.
The 20 rds mag is camouflage, so that an otherwise BR IV gun can hide among BR I SMGs. Itās accurate, controllable, fast firing and deals good DPS at all but very long ranges.