Why would that make ps4 version inferior? They'll be the same.
that in itself would not make the PS4 inferior, but from a business standpoint it makes perfect sense for Nintendo to make the NX more powerful than the PS4.
My Reasons:
1 if the PS4 is more powerful and assuming they cost the same, why would anybody in their right mind (not counting fanboys or first party games) choose the NX.
2 the NX will have to compete with the PS4 and Xbone for about 3 years, and then PS5 and whatever MS calls their NextBox for another 3 years, so the NX needs to be future proof.
3 Only reason the NX comes so fast after the Wii U, is that the Wii U is a sales disaster IMHO
4 With the NX being at least 1,5 years away, it is likely that AMD will be able to produce APU's smaller than 28Nm, thereby enabling greater amount of transistors on chip.
One important issue I feel Nintendo will have to struggle with is the likely 250watt max power limit in order to keep cost and size down.
Regarding "The PS4 version of the game is being developed in Unreal Engine 4, which suggests that Nintendo's next console will have the horsepower to drive Epic's new engine.
Pretty sure the "new engine" is referring to UE4." : could be, but I feel my points above still stands.