Haven't played it but iirc the story is that Light and Wily spent their lives making stronger robots to outdo each other and X and Zero were their ultimate creations but they both died before the two robots were used.
Then centuries passed and people digged the robots and turned them on, so they teamed up to fight the new bad guys.
So Light used MM as a skeleton to create X, and simply have X a few more skills? That it?
They are different individuals though. This is a series about sentient robots
So they have different personalities and thats really it? Same base skeleton and design?
I mean if that's where you're going then Wario and Waluigi are the same character.