Yeah I think they're basically just taking the Wii U first fiscal year + 3DS first fiscal year and combining them, as NX is probably an over-arching product line of various different hardware.
GBA and GameCube both launched in 2001 too and they sold about 20 million combined by fiscal year end (March 2002).
In which case 10-20 million is reasonable I guess. It doesn't really matter anyway, Nintendo can project whatever they want, the market has the final word as always.







