That's hardly a fair comparision. Wii TP and GC TP are the same game, launched at virtually the same time (mere weeks varying a little by region), so the sales really do need to be added together. No-one reports pokemon sales seperately for two different versions of the same game, even with the minor differences, while later remakes are counted separately. It's the same deal with TP Wii and TP GC.
It's certainly not the same thing as a 13 year gap between a game and it's remake. Otherwise, we have to wait until at least 2019 to see if a similar remake is happening in the same period of time, then 3 more years to accurately compare the sales.
OoT 3D is the same game as OoT mechanically. they just updated the graphics. it is not a remake like many think and it is actually a very enhanced port.
and GC and Wii TP have major control differences.