hairy_hen said:

Grievous was a stupid, worthless piece of shist in all ways.

His 'voice-acting', if you can call it that, was done by Matthew Wood.

The same Matthew Wood who is responsible for the absolute garbage that is the 2004 dvd sound mix for ANH.

Need I say more?

People have been known for being good writers and shit directors, or vice versa. What makes you think that one's abilities as a sound mixer (I haven't analyzed the sound mixing in any movies and have no idea what you're talking about with ANH) has ANY bearing on one's abilities as a voice actor?

Just in case this was somehow, somewhat a response to what I said, you very obviously missed the whole point. If not, then you didn't ;)