I am looking for pure scheming or strategist type male lead [Without Harem.] Best example and inspiration for this thread is "The Grandmaster Strategist" which is one of my all time favorite novels. My favorite thing about TGS MC is that his plans are unpredictable and that is the core excitement that comes from those novels. I don't want the world to be dumb but I want the MC to be smart if that makes sense.
I can very much recommend Classroom of the Elite. The MC is male and attends a futuristic high school. You can see fairly early that he is intelligent, but his schemes become more apparent in the latter half of the first volume.