I would like to formally propose the inclusion of 6v6 for casual multiplayer. It would accommodate 3 tactical and objective based game modes from the following titles.
Halo 3 - Flag Rally (Squad Battle)
Flag Rally is a game variant of the Territories gametype. In this mode, the basic rules of Land Grab apply, except that territories can be captured more quickly. However, they can also be captured more quickly from you by the enemy, as no territories are locked. Therefore, teamwork is critical in order to focus on both offence and defense simultaneously. Any maps used would have to include fun power weapons and vehicles.
Halo: Reach - Invasion ans 3-Plot Territories
Halo: 2 and 2A - 3 Plots
Halo 4 - Dominion
I believe this will help get more people playing these fun game modes and will save Invasion from being clumped together with competitive rankings that don't actually work.
It's an easy thing to do and I am 100% sure the community will love it. Can we make this happen 343i?
How I see it arranged:
[Reach]  [2a]