ok ken was originally a clone of ryu, but by SF2 they played completely different, ken being luigified so-to-speak. next, is that 27 million sold from just the classic megaman series, or from all of the different megaman series put together? something tells me it is a collective which really doesn't hold up in this debate since we are discussing just the classic megaman, and not .EXE or zero.
neither megaman or ryu would be clones, mainly because they have enough originality to be their own character. first off, ryu is twice as big as mario and luigi, so that alone makes cloning nearly impossible. next, hydoken is around 4 times stronger than luigi's puny fireball, it is bigger, and it travels at a different speed. if anything it is close to a charged samus ball accept you don't have to charge it. in the hurricane kick move, ryu moves across the screen, what he doesn't do is stand in one place and spin like mario's VB move. if anything it cold be compared to DK's ^B move, accept the size, speed, distance, and lag are allot different. and on to the topic of ryu's ^B, it doesn't catch the opponent in it like mario's ^B, and it has more distance and is slower than luigi's ^B, also the lag affects of this attack are unique to ryu alone. in conclusion, ryu would be very far from a mario or even a luigi clone.