Yeah but he really doesn't have any where to jump around in here and he's on ice so he'll be sliding around. And even if Sokka gets hit he has armor on, so he couldn't one shot him, only knock him back.
19:10 to 19:55, he takes down 3 battlements ( with help ) and slices straight through metal, So i'm pretty sure he could cut thought Beast with no problem
So I don't really know what Beast could do, he could get up close to Sokka and try to hit him but Sokka's reflexes are good and he could block and counter attack with the sword. Beast could try to jump around him and strike from behind but the ice would make him slip and he could be easily taken then. Soooo yeah, Sokka can counter almost any attack Beast can do.