I wanted to chime in and say that I like both of Burbin’s ideas. It did feel funny for Grievous to be focused on the witches before he has even taken care of the Jedi in his lair. Like, he has Jedi running around in his house and he’s like, “I need to go kill Ventress and those witches!”
I think it fits for him. He’s not considering Fisto much of a threat but he’s eager to go out and kill Ventress at last.