I'm all for amalgamating Grevious and Maul. A non force-user wielding lightsabers never sat right with me.
Except for Han gutting the Taun Taun.
Only thing would be, how would Maul/Grevious work in an edit where Dooku is good, and the Seperatists are, to a degree, in the right.
I suppose it could be explained as Palpatine pulling strings - infiltrating the opposing side with a loyal agent of his own.