Unless it's the Broadsword table, this Longsword table isn't fully updated.
I checked the Fire and Deep infusions of both the Longsword and the Broadsword because I thought the higher damage made the Broadsword better with a split damage infusion.
It does. Obviously both are useful.
Except, one of these is not updated. Both swords are very very close in stats, but here, there's like 20-30 AR of difference, and if you check other more regulated tables on reddit, you'll find they're consistent with the game.
I'm pretty sure I remember a nerf to straight swords a long time ago. Weird that it's not edited here yet.