You can't say games are different and then use another comparison lol.

So are we using comparisons or aren't we?

I can do the same thing. Tetris was once one of the most popular games of all time, gameplay remained the same and now it's not nearly as popular.

You're comparing Halo to a game that literally started out in arcdes, in the mid 1980's, and has nothing to do with the shooter genre. Whereas I'm comparing Halo to another FPS, that launched within a couple years of one another.

In reality GoW is the closet analogue to Halo. It is a Microsoft exclusive franchise that moved systems in it's first trilogy and now has slowed down in sales.

GoW4 sold more than twice as much as Judgment. I have no idea about population counts, so I really can't speak intelligently about it.

It's a far more apt comparison than a PC game that can run on a computer 18 years old.

Comparing two FPS games, that launched within a couple years of one another, versus comparing to a cover based, TPS that launched over a year after the second installment of Halo...