I’ve been using the BSA Thompson for a long time, and post merge it’s a pretty solid weapon for BRII. Using it with Assaulter IV’s has been pretty good, If I had the gold orders I’d personally consider getting 3 more of them so that my assaulter squad is loaded with them.
It’s a matter of preference: if you want a high rof SMG with a short mag, or the best grease gun with a silencer that provides a tangible advantage in cqb, more than just a gimmick in my eyes.
They both do good damage and can be effective in the right hands. I don’t have the bsa, but I’ve got the USMC Thompson squad and while I do find the short mag problematic at times, It makes up for it with a very fast reload. It can be deadly in cqb but I’m not very successful with it at longer ranges.
The bsa doesn’t have as fast a reload, in fact you’ll spend almost a second longer reloading a mag than you will emptying it. The m3 has a slow rof but it’s very controllable and accurate so you’re getting more shots on target, and it still reloads a 30rnd mag faster than the bsa 20rnd.