Kirby was mainly an artist and co-created some Marvel characters in design. His writing however, was mediocre.
Lee was mainly a writer, but lacked the artistic hand of drawing. However, he was a genius writer and created almost most the characters we've been reading about these passed 40+ [almost 50] years. Lee unlike Kirby had also a better conceptual understanding of science, knowing about space-time and parallel universe before the science of Quantum-Physics became popularized in the 1980's. He created Dr. Strange to introduce characters BEYOND cosmic level because he knew that science can only go so far, so he needed a medium to venture beyond that.
This is not a stalemate:
Stan Lee wins 8/10
The 2 points go to Kirby with his character designs and overall art work.