In this author's modest opinion, George Lucas' "Star Wars" prequel trilogy has good ideas but disjointed execution. Consider Count Dooku as an illustration. On paper, it seems exciting to have an ethically dubious Force user who eventually realises the shortcomings of the Jedi Order before giving in to the dark side. After making his debut in 2002's "Attack of the Clones," the character's potential would be realised in later "Star Wars" films. However, the way Dooku is portrayed in the Lucas trilogy strips him of a lot of his complexity before his death at the beginning of the trilogy's concluding chapter, "Revenge of the Sith."
Dooku only truly makes an effect in the prequel movies because of Christopher Lee and the gravitas he lends to the part. Lee was the uncommon performer who had just as much screen presence acting in live-action as he did in animation thanks to his powerful, scary vocals. One only needs to look at his IMDb page to know that he was frequently a standout in the comparatively few animated productions and video games he provided his voice for.
Therefore, it comes as no surprise that Lee returned to voice Dooku in the animated movie "Star Wars: The Clone Wars." The 2008 film, infamously made up of material pieced together from the original "Clone Wars" animation series' three-part premiere, was given the go-ahead for a theatrical distribution by Warner Bros. Pictures, the film's distributor. No, it wasn't. Although Lee replaced Corey Burton as the voice of Dooku in the movie, it wasn't because the legendary Hammer Horror actor thought Burton's performance needed improvement. On the contrary, it appears that Lee was hesitant to turn him over at all.
Burton thankfully received the recognition he deserved in due time. He would return to voice Dooku and other characters in the animated "Clone Wars" TV series, notably Cad Bane, and most recently portrayed a younger version of Dooku in "Tales of the Jedi" by "Clone Wars" director and producer Dave Filoni. Bryan Young, a writer for /Film, said that Skywalker Sound's supervising editor Matt Wood had informed him that Lee was hesitant to replace Burton in the "Clone Wars" movie, feeling that he was "very fantastic," in an interview with Burton to promote the animated anthology series. Burton attested that Wood had said the same thing to him:
"Yes, indeed. It's incredibly flattering that Matt told me that. Although Christopher Lee was a well-known actor, he was a character actor just like the rest of us. 'What do you need me for?' is all. Absolutely, I'll take up that role. He also seems to dig my take on his Count Dooku character. It's simply that one of the actor's agents noticed that there was this movie and in their contracts, all of the film performers had the right of first refusal. I don't think from what I heard that he was all that interested on performing that job anyhow."
Burton was obviously unhappy to be replaced, especially after Lucas informed him and the other original "You now have a licence, Clone Wars cast. Now that it's animated, you can sort of claim ownership of these character voices." Again, though, Burton would eventually come to give Dooku in animation his own unique stamp. There might even be a part of him that is thankful to Lee, given how terribly the "Clone Wars" movie was received (there's a reason you don't see it getting new reviews like movies like "Attack of the Clones" have).
Disney+ offers "Tales of the Jedi" for streaming.