Well, dunno how dark it's likely to get, it could just be cartoony dark. I wouldn't say that the Dying Earth stories were particularly dark - the mian character for a large chunk of them is Cugel, a self-deluded rogue who thinks he's better at everything than he is, and the two books featuring him are a picaresque wander across a land of wierd things. Ditto Gene Wolf, in many ways.
Besides, comic relief is always welcome. A small techie type sounds like a good enough fit to me, if you want to go with him as the main character and forget the duo. Maybe this round we lose the lizardman due to an exploding cannon (this high through-put of assistants could even become a running joke).
Anyway, just some thoughts.