I think you underestimate the western sales. This game is the FF most geared towards the west and it will certainly pick up a lot of great reviews stimulating the saleseven more. It's basically the JRPG Witcher.

PS4 - 79%
X1 - 21%

Maybe PS4 will have even less. Type-0 HD which is PSP port sold 5:1 so FFXV will sell something like this

It's a little hard to guess, since the sales are likely to be lower than past mainline FF games which, in turn, makes for larger percentages on the Xbox side, but 4 to 1 sounds about right. 

if thats the case then im going with 100% for ps4 and 0% for x1.

Finally a reasonable prediction in this thread.

Why would you think the sales are lower? And if you think that it's less popular than other FFs it would make it even more disproportionally unpopular on X1.

If it's very much PS4 where do the 20% come from?

90% PS4.

Note: I have KH 2.8 outselling the Xbox version of FF XV.

PS Quatro 89%
Xbono 11%

In the other thread, I predicted 5.6ml on PS4 and 1.45ml on XB1. That's around 80% PS4 nad 20%XBO.