Making it even harder to say: the 8080 was based on the 8008. Even though the 8080 was based on the same instruction set as the 8008, it wasn't binary compatible. I assume that means the instruction encoding was different, which means those engineers probably did as much as the could to clean things up while designing the 8080.

Of course, the 8008's origins (along with the completely unrelated 4004) were outside of Intel. They were hired to design custom ICs. The 8008's architecture was dictated by a CTC terminal. While Intel designed the 4004, it was only intended to be used in calculators. Intel, and its engineers, probably put relatively little thought into microprocessor architecture until the 8080.

They did eventually design their own clean-sheet instruction set for Z8000.