This is only my opinion, but:
Team Snipers and Slayer Pro are fairly similar. This could work.
SWAT plays completely different than the others, it is more tactical.
I can make the same comparison for Team Objective.
Oddball and Regicide both involve gaining and protecting a moving objective.
KoTH revolves around holding a static position.
KoTH, Race and Territories being paired together would make sense. They all involve moving to and holding a piece of the map. But it doesn’t really fit with Oddball and Regicide, which are more dynamic.
I can make yet another comparison. CTF and Assault being paired together would make sense because they both involve moving an object somewhere else, mainly to or from established bases. But CTF doesn’t have anything in common with Regicide or Slayer.
Similar gametypes can be paired together, but contrasting ones should remain separate.
Therefore, this is how I would organize playlists.
Slayer
Infinity, Throwdown, Pro
Big Team Battle
All gametypes, this would be the exception to the rule since we can’t have a ton of different BTB playlists.
Heavies
Rockets, Swords, Shotguns, Snipers
Turf
Dominion, KoTH, Territories, Extraction
Invasion
CTF, Assault, 1 flag, 1 bomb, Invasion
Control
Oddball, Juggernaut, Regicide, VIP
SWAT
Infection