I mean, yes and no. The "brace of pistols" was a thing. But it was kind of... hardcore. Ideally the rules would allow for a PC to go that route and carry, say, four to six guns. But it shouldn't incentivize that as the normal best practice in combat, because it definitely wasn't.
I'm almost tempted to steal an idea from video games and introduce the concept of "weapon sets". The idea being you can only have so many weapons ready for immediate use at a time. Can't strap sixteen different swords to your belt, can't carry twelve holstered pistols. So maybe the brace of pistols guy can have two pistols in "set 1", two more in "set 2", and a final two in "set 3" that he got from a class feature or feat. But then that's it for him: no backup melee weapon feasible. In contrast, another PC might instead have one pistol in "set 1" and then a sword-cane and cape in "set 2".