Popularity trumps relevancy? Maybe, but when faced with time constraints? Then it is relevancy that trumps popularity. Ike > Roy. Lucario > Mewtwo. After all, Nintendo wants to attract potential customers to their new games through Smash. They did want to sell Fire Emblem Path of Radiance and Pokemon Diamond & Pearl more than they do with Fire Emblem Sword of Seals and Pokemon FireRed & LeafGreen. A business wants to sell the new products first before the old products. That's last-in, first-out. The LIFO method.
You really have issues with comphrehension, do you?
1. Lucario and Ike didn't replace Mewtwo and Roy. Get this out of your skull.
While they were both finished first, they weren't in OVER them, as Ike and Lucario were both finished prior to the time issues. You know who else was part of the time issues? Jigglypuff. Had Jigglypuff not make it, would you be arguing that Pokemon Trainer replaced her? When it all comes down to it, Jigglypuff was Mewtwo's biggest obstacle, not Lucario.
2. Correct me if I'm wrong, but isn't SAKURAI in charge of characters, not NINTENDO?
Sakurai doesn't give a **** about trying to cater to what will help Nintendo in sales. Case in point, Mother; How is Lucas going to help Mother 3's sales, when GBA is dead, and the game is Japan exclusive? Anyone who gave a crap about Mother 3 has already got the game or has a Rom of it for their computer.
While Ike and Lucario were of outside influence, it was not like Sakurai was held at gunpoint and told to get rid of Roy and Mewtwo for not being relevant (otherwise, Jigglypuff would've been gone as well).
And Ike was merely SUGGESTED because Sakurai wanted a new FE character (which means anyone from after FE6, Roy's game) and didn't know who to pick. Don't act as though he included Ike because he was new and relevant, and would help boost sales, as it wasn't the case.