Social (8 Playlists):
(4v4) Quickplay - Slayer, strongholds, attrition, king of the hill, one flag, oddball, land grab, etc.
(4v4) Team Snipers - Team Snipers (S7s Only). Remove Brute Snipers + Snipers and Shottys.
(2v2) Doubles - Slayer, Oddball, Snipers (S7s Only), Ninja Slayer, Rocket Repulsors, Fiesta, etc.
(8 Player FFA) Rumble Pit - Remove Oddball (Vampireball plays much better FFA). Add FFA Snipers (S7 Snipers Only), Escalation Slayer, One in the Chamber, etc.
(4v4) Action Sack - Fiesta, Ninja Slayer, Rocket Repulsors, Skewers Only, Shottys and Snipers, Pit of Joy, etc.
(4v4) Tactical Slayer - Remove Manglers and Stalker.
(12v12) Big Team Battle
Weekly Rotating Playlist - Infection, Griball, Last Spartan Standing, etc. (Plus the Event Playlist when active)
Remove Bot Bootcamp. Its pointless when you can do the same thing with bots in customs and academy.
All major areas covered. Monthly rotating playlist allows for these big non traditional modes which cant easily fit into a category or maintain a solid playercount at ALL times. Quickplay covers a social version of traditional Halo. Rumble Pit and Doubles are the social versions of their ranked counterparts but with more fun/casual modes added into the mix. Action sack is the “party” playlist. Tactical Slayer is obviously for the SWAT fans. And then obviously theres BTB.
Ranked (5 Playlists):
Arena: 4v4 Oddball/Strongholds/Capture the Flag/King of the Hill/Slayer
Lone Wolves: 6 Player FFA Slayer
Doubles: 2v2 Slayer (maybe Oddball and KOTH too?)
Attrition: 4v4 Attrition
Featured: Weekly or Monthly Rotating (FFA Snipers, 4v4 Snipers, SWAT, etc.)
Covers all areas without too many playlists. Traditional HCS gameplay with Arena, Solo skill shown with Lone Wolves, Doubles for solos and small teams, Attrition for a more intense single life style mode and the featured playlist gives a more fun/less stressful ranked mode.
Conclusion:
With all of these playlists and Forge + Customs Browser the game should be pretty set for content and modes to play for a long time. Theres a good amount of variation, all major types of gameplay are covered. There arent really any irrelevant playlists and there is something for everyone.
With these changes + performance fixes (desync, crashing, etc.) + player chosen matchmaking preferences (Skill or Connection) + general fixes (Progression, Customization, etc.) this game could become GREAT.