I think the difference in the material of both is quite stark too.

Fowler's books are very descriptive, Refactoring is clearly a list of strategies. And there's even conflicting advice, since it's meant to be a catalog rather than a rule book.

Clean Code on the other hand is very prescriptive.

Not that it matters, the people that wrote the GoF Patterns book have been saying for years that their book is descriptive but very few people hear it.