An idea I read on James’s blog Grognardia long ago, which I quite liked, was what he called “D&D is always right”. Rather than assume the idiot choices the designer of some old module from the 80s made are incorrect, give them the benefit of the doubt! Try and work out how the oddly placed monsters, treasure, and traps fit into a coherent whole. Treat it like a creative exercise and you’ll end up with something good. My dilemma is I can’t actually find this blog post, though i’m sure it exists!