It is pretty well established that Nagai Go's Mazinger series is a monolith to the development of Japan's modern day robot fiction. First published as a manga in 1972, it paved the way by introducing all sorts of super robot concepts that are consider standard tropes today. Among these are a flood of fantastic mechanical designs with unique attributes and abilities. With that in mind, it shouldn't be all too surprising if I told you that among the 80+ boss characters of Rockman, there would be some that would pay homage and/or take inspiration from the mechanical giants found in Mazinger Series. Allow me to explain the "like peas in a pod" Boss Characters and their Mazinger Series origins.
Mazinger-Z and Hardman
Garada-K7 and Cutman

Boomerang Sickle From
Mazinger-Z Anime (1972)
Stronger-T4 and Airman

Super Robot Wars Z2