Nintendo should just do whatever in terms of when they release as long as they continue to profit
Sales wise, it won't make a difference. The people are going to pick who they pick.
The PS1 came out before the N64- the PS1 got the lion share
The PS2 came out before the Gamecube- the PS2 got the lion share
The PS3 literally came out with the Wii- The Wii got the lion share (you can say the price is a factor all you want, they still had the lion share even if that is true)
The PS4 came out after the Wii U- the PS4 got the lion share thus far.
So as you can see, it doesn't matter when they come out.