I stand by my argument that Time man and Oil man are retcons made solely for the sake of completing the circle of 8. I mean, they seriously weren't necessary.
I don't see why that's even a factor. All the boss robots in every game a result of establishing that same old circle of 8. It is a long established tradition simply because it works. It gives the player the expected amount of new content in terms of bosses, music, stages and weapons. Thus, you should consider it as such; they gave you two new bosses to give the player new challenges and replay value. They made Rockman Rockman much more than a 1:1 remake by making it on par with the other games. But not just that, the game actually went and exceeded all other titles by allowing you to play as every boss, and giving us the ability to make every stage of our own liking.
Besides, the Numbers make a lot more sense with TimeMan and OilMan. 8 robots were used by Wily, and MetalMan is the ninth robot in the numbering. Rock and Roll shouldn't be in the list of robots that took over the world each mainstream game.
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