I’ve actually had this same sort of idea for creating a new Episode II out of Clone Wars episodes (both Filoni’s and Tartakovsky’s) for my own version of the Prequel Trilogy (Episode II as Episode I, this fan edit as Episode II and Episode III as is).
That sounds interesting. I’d really like this idea. But you should edit Attack of the Clones to introduce some flashbacks from The Phantom Menace in order to establish Anakin’s relationship with his mother and why it’s important in Attack of the Clones itself, otherwise it couldn’t work as Episode I.