Honestly, I think you're overestimating the importance of each individual track. I remember thinking the same thing when I was organizing Road Rage two years ago and coming to the realization that Mario Kart has maybe one "iconic" song per game, at best. Maybe two or three more "good" songs per game each.
But a lot of what you have to consider here as a co-director of this album is what goals we can realistically achieve and what sacrifices we have to make to have a finished product we can be proud of. Idealism is great and all, but you have to be able to recognize when goals are getting too big. And if you let the dream of having a gigantic project interfere too much with the goal of actually getting the project done, both ideas are going to fall through and we'll be left with nothing at all.
Beyond that, you're clearly looking at this with the mindset that there are specific iconic themes. That means that unless you pick out the tracklist for people to claim ahead of time, rather than allowing ReMixers freedom to choose their own source material, you're going to be disappointed with the selection of music no matter how big it is, because the musicians' favorite songs from the series isn't necessarily going to align with your own idea of what's "iconic."
But seriously dude, please add me on Skype. We've got to talk this through more directly.