I’d much rather lay it out like this:
Ranked
Team Slayer (Pro, Legendary, Legendary BRs)
Big Team Battle (12v12, Pro, Legendary, Pro Objectives)
Team Objective (5v5, Pro and Legendary Objectives)
Team Throwdown (4v4, Pro, Legendary, Legendary BRs, Extraction BRs, CTF BRs, CTF Pro, Extraction Pro)
SWAT (SWAT, SWAT Magnums, Covenant SWAT, Forerunner SWAT)
Team Snipers (4v4, Snipers, Snipers Pro)
Rumble Pit (6 Players, Pro, Legendary, Pro Objectives)
Social
Invasion (12v12, Invasion, Invasion Skirmish)
Social BTB (Identical Settings to ranked + Infinity Slayer)
Social Skirmish (5v5, Identical Settings to Ranked TS)
Action Sack (FFA, AS Variants)
Flood/Infection (16 Players, 3 Flood to start, Flood/Infection, Hivemind)
Multi Team (3v3v3v3, Infinity and Pro variant of Slayer and Objectives)
Grifball (Duh)
Social Objective (5v5 Identical Settings to Ranked Obj + Infinity Variants)
Team Destruction (8v8, Assault, Ricochet, Pro/Infinity Variants)
Pit of Joy (9 Players, Pro and Infinity Slayer/Objective Variants, FFA)
Infinity Slayer (4v4, Pure Infinity Slayer on TS maps)
I think this would please everyone, leaving Infinity aside a Social Slayer Playlist, and Pro a Social Playlist, alongside leaving the competitive edge to Pro and Legendary.