So, if D&D had rules for muzzle-loading flintlocks, and there was a feat allowing you to fire flintlock A in your right hand (main action), and flintlock B in your left hand (bonus action), *every round*, would you have characters do that? You don't care that reloading a flintlock IRL takes a free hand and several steps (pour powder, load wadding, load bullet, ram tight, prime pan, reset striker)?
Is this any different from one-handed crossbows which draw their own bowstring taut enough to hurl a bolt, AND place a new bolt in the groove, instantly, without the use of a free hand?
If D&D had a feat for PCs wielding a halberd in one hand and a longbow in the other, attacking with both in the same round, while simultaneously equipping a shield for +2 AC, while also sliding down a staircase on that shield, would you have characters do that? In the end, sir, do you have no sense of shame?
If you wanna go Chow Yun Fat, then give your PCs clip-fed semi-automatic handguns. Heck, go open-bolt and give them Uzis. That requires less suspension of disbelief. I mean, I know what dual handgun looks like. I know what a clip-fed crossbow looks like, too. The part where the string pulls itself back each time just baffles me; I don't know how to visualize it. "Where did they get Uzis, how do they manage the recoil, and how many rounds are left in the clip?" are minor questions by comparison.