There's a lot of cunning and cleverness going on in The Witches. Our narrator, Grandmamma, and The Grand High Witch all do their share of clever scheming. Important to remember is that, in this book, cleverness is not attributed to entire groups, but rather to individuals. For instance, it seems like the Grand High Witch does all the scheming, while the other witches just play along. This is true for our narrator and Grandmamma, too. Not all kids or all grandmas are clever, just our dynamic duo. Remember, in order for these clever characters to shine, they need to be juxtaposed with some very un-clever characters, like, say, Mr Stringer or Bruno Jenkins.
Our narrator is the brains behind the operation. He's way more clever than Grandmamma.
Mice are apparently clever little rodents. The narrator seems to come up with much more advanced ideas once he's transformed.