This is just confusing. Their arms are the same in RO as in ANH??? What adywan did was chnage who’s arm got chopped off, to match what happens in the scene. We see Dr Evazan pull a gun to shoot Ben, then Ben cuts at Evazan and Ponda’s arm ends up on the floor with the blaster. So Ady switch the arms to make it so that Evazan’s arm is on the floor, becuase it makes more sence with what we saw happen. It was a mistake born form Geoge Lucas’s inexperiance with fight scene at the time, quite why he never thought to adress it as one of the many chnages he made in his SE I can’t fathom.
Evazan is also the one screaming in pain after Obi-Wan pulls out his lightsaber.
Because he was also sliced, he just wasn’t dismembered. Canonically, Obi-Wan got both of them with his swipes.
I just personally find it odd to go out the way to contradict both the original film and canon, but I’m not the one providing the edit, so of course Adywan can and should do whatever he wants to do.