Why didn't you use the same logic for your Halo 5 prediction?
I did. Halo 3 and i think 2 had those sales with around the same userbase
See this is the problem right here, you base you facts using cherry picked positive data for stuff relating to one console while you find ways to not do that with stuff relating to another consoles.
You go on about install base, what did Halo 4 sell? 9/10M on a 80M install base? You predicted over 7M of Halo 5 sales in 2 months on a 15M install base. I'm just a little mythed why you chose to be optimistic for Halo 5 even though sales for the series peaked at 3 and Xbox One is struggling to get any momentum. While being a little negative on Unharted sales even though PS4 is has massive momentum going for it, the Uncharted series sales trend has been going up (has been since the first game) and Uncharted 4 will probably have the most hype of all the Uncharteds.
It might sell less because of install base and the fact it's releasing in a non-holiday part of the year but a little bit of consistency would be nice.