Well the gun variation is probably due to people liking bl1 loot system, there was no gun gimmicks and no different manufacturer parts the biggest variation in bl2 was the hyperion barrel which grants the bonus to crit damage the rest are minor changes in stats for the gun. Bl1 you could have a pistol shoot multiple pellets if it dropped with the masher barrel like the maggie but it could come with any revolver not just Jakobs iirc.
You could have hybrid legendaries,2 legs in 1, because some legendaries have the special effect from their accessories. For example if they kept that system in bl2 you could’ve got a skull masher mixed with lyuda or a hornet mixed with a Maggie, I don’t think it was all legendaries but most of them could be hybrids.
Maliwan, dahl, and vladof made shotguns. Torgue made smg and snipers, hyperion, and Tediore made AR’s. Also there was no bandit or scav, there was s&s munitions, they had one more manufacturer too atlas.
So you start to see that there was greater variation in what kinds of guns you could get. On the flip side there was no legendary grenades or shields so bl2 wins on that front sorry for the wall of text btw just felt like writing a bunch