Third party support is irrelevant, that model doesn't work for Nintendo and hasn't since 1995, Nintendo should accept it and move on.
They should focus instead on fast tracking more exclusives. They also need to pull their head out of their own rear ends and start marketing their own core IP to rebuild the audience there.
Fire Emblem seems to be getting a decent push in the West, and seems to be selling well as a result. Other games should get a similar push. There better be a Bayonetta 2 special edition and some real marketing throw behind it.
Things like The Last Story, Xenoblade, GoldenEye, etc. needed to be released earlier in the life cycle for the original Wii, they all would've sold better. Nintendo needs to recoginize that they need higher quality core exclusives earlier in the console life cycle.
Releasing them in the dying years of a Nintendo console is always problematic because the audience has moved on by that point. It was the same even with the N64, Perfect Dark and Conker's Bad Fur Day deserved higher sales, but just came out way too late.