Gears is a high selling game without bundling. Its one of the few games that can sell 5m+ without bundling.
However, Halo is also one of those games plus it gets bundled and has a stronger community. Gears has a very strong community as well, but the multiplayer has a much higher learning curve which makes a lot of people give up quickly.
So now that Gears is a MIcrosoft owned ip, i can see it getting bundled more. So it may increase in sales (Maybe) but it wont outsell Halo 5.







