If you compare them as is, Light Yagami can be considered slightly more intelligent than Norman. He was able to go on par with an experienced detective. Plus, he’s shown some creativity with the ways he makes his traps. But if you give them more time, Norman would eventually be more intelligent than Light. Norman’s problem is that he’s a young genius who barely knows how the human world works yet while Light already knows the ins and outs of Japanese society. So if you made them into something like neighbors, Norman would be the smarter kid that Light might have looked up to.