Actually not really. I discovered that "time" is a factor in determining the true relevance of "flagships". It is something I like to call "generation sales". Basically how well a franchise sells over the course of the entire generation.
Wii has Mario Galaxy 1, Mario Galaxy 2, New Super Mario Bros if I am not mistaken. Nevermind the spinoff sales like Mario Party or Mario Kart. Mario sold like what......40+ million dedicated Mario games this gen on Wii.
360 Halo sales (FPS ones) are comprised of Halo 3, Halo 3 ODST, and Halo Reach. Combined total of 26+ million Halo sales this gen.
PS3 flagship GT5 only sold 7 million. If you'd like ill throw in the demo for another 4 million for a combined total of 11+ million.
Being a one hit wonder just doesn't cut it nowadays. True flagships deserve multiple games per gen, and sell amazing each time. That is why in my opinion, Uncharted is the new flagship IP, since it now has higher "generation sales" then GT, which is a combined total of 13 million I believe.
Time isn't a factor at all.
2D Mario and 3D Mario are totally different, don't try to mix them up. Nintendo's "flagship" title is 2D Mario. Always has been, always will be. 3D Mario, as much as Nintendo want it to be, isn't as big or important as 2D Mario.
It looks to me like you're adding up the sales of the games. So let's do a "sales on average" thing, shall we? I also assume we're only using home consoles here, as you neglected DS/PSP from your lists. We'll do Mario Platformers (just to be fair to you) on Wii, Halo FPS on 360 and Gran Turismo 5 (I assume you don't want to count a "demo" in with those GT5 sales) on PS3.
Mario Platformers on Wii have sold 47.25 Million units over the space of 5 games. A current average of 9,450,000 units per game.
Halo FPS on the 360 have sold 27.9 Million units over the space of 4 games. A current average of 6,975,000 per game.
Gran Turismo 5 on the PS3 has sold 7.13 Million units alone. An average of 7,130,000 per game. If you want to add in the Demo, which has sold 5 Million btw not the 4 we have here... Gran Turismo currently averages 6.1 Million units per "game".
If we're talking sales per release, Sony have a Halo. They don't have a Mario, but then again... Only Activision have one of them.
Fun fact - New Super Mario Bros. Wii has almost sold as much as those 4 Halo games combined.