If you look closely, he does have 4 lightsabers on his belt. WTH?? Does that mean Grievous can use the Force? I.e., the biological part of him? I know you don't have to be a Force user to use a lightsaber, but to try using one without the Force...it would be easy to hurt yourself. I suppose if he's an incredibly advanced android, he'd be able to execute all the proper moves without the Force... I don't really see him as being a prototype for Vader - he's way more robotic. More like King of the Droids.