Greatswords were simply called two-handed swords in earlier editions of D&D, they were not new for 3rd edition. (But in 1st and 2nd ed AD&D damage was different vs Small/Medium creatures and vs Large - 1d10 vs 3d6). Historically two-handed swords were definitely used, primarily in the late medieval period. There are many accounts about the use of the weapons and the troops that used them. But oh yeah, they were definitely not primarily used for fencing as such, although there are preserved manuals on the subject. I believe the sometimes stupidly oversized representation in D&Dis more down to interpretations of the artists than an actual intent by the devs to have Final Fantasy type monstrosities in the game.
But since most weapons are upscaled in BG3 to some extent, I thought for a long while that the longswords my Tav and Laezel started with were greatswords. They still look somewhat right though, whereas the morningstar... Just no, gods.
Once you get a proper greatsword for Laezel it looks downright silly when on her back though - but I like how she often carries it in her hands leaning it on a shoulder when idling, makes it look like it actually has weight.
