what would he make of Napoleon?

As long as Napoleon didn't make a pass at Harriet (having been misled by the bad-girl eyes into thinking she'd be up for it) I'm sure they'd get along fine. Rather bizarrely, given that the show runners thought we couldn't possibly be interested in details of the agents' private lives, it's canon that one of Napoleon's grandfathers was an ambassador and the other an admiral, so he's used to moving in F.O. circles.