Bren cant have the same dps as the mg42 because the mg42 is so good to offset grens model count so they can keep dps up. Not only can tommies offset that with a small cost (for all infantry they build) they are also more durable to begin with but also get the same rec acc buff (-23%) a whole vet level sooner
Thr problem with dual wields iis that it allows already superiour units to widen that gap to ungodly unmatchable levels.
Double guns make fresh squads fight like vetted squads and vetted squads near undefeatable.
Yeah now that you mention it making the Bren a mg42 copy would probably be a bit op. Still the Bren would need a slight buff if made a single wield IMO.
My biggest worry is that they changed the Bren/Bar to a single wield but don't balance it properly in which the upgrades become up.
I do agree however the Dual wield needs to be looked at as single upgrades imo is better for game balance/health