I think he can. When he did Boss in Republic Commando, he sounds completely different from Commander Cody in Revenge of the Sith, besides the same voice. Boss is much more gruff while Cody is lighter and even jokes with Obi-Wan. He hasn't been given much opportunity to do what Dee has done, but I bet he would.
I'm not sure whether he really likes the part and is always happy to come back (like in BFEA), or if it's just another pay check to him. That's probably going to be the key in his performance.