Each brawl in ConfigureMatchmaker() is a small queue template: player counts plus a levelsDesc of map = {gameplayId} plus a matchmaking query flag. Football is 6 players on map football (mode 21); GTDM is a 2-player duel on da_prototype (mode 13); ATDM/april-team-DM share paper_airplanes (mode 26).

local footballQueueTemplate = {
  maxPlayers = 6, optimalPlayers = 6, minPlayers = 2,
  maxExpandTime = 0, regionLocalizedTimeInQueue = 1, maxTimeInQueue = 1,
  levelsDesc = { football = { 21 }, },
  query = { ["mmParams.football"] = 1 },
  special = { brawl = 1 },
}
local gtdmQueueTemplate = {
  maxPlayers = 2, optimalPlayers = 2, minPlayers = 2,
  levelsDesc = { da_prototype = { 13 }, },
  query = { ["mmParams.gtdm"] = 1 },
  special = { brawl = 1 },
}
local atdmQueueTemplate = {
  maxPlayers = 8, optimalPlayers = 8, minPlayers = 2,
  levelsDesc = { paper_airplanes = { 26 }, },
  query = { ["mmParams.atdm"] = 1 },
  special = { brawl = 1 },
}
Raise minPlayers if a brawl should only start full, lower it to let two friends start it alone. maxExpandTime = 0 means the lobby never relaxes its team rules.
Additional Notes: 

Mode IDs: 21 football, 13 GTDM, 26 ATDM.

Comments

5 + 13 =
Solve this simple math problem and enter the result. E.g. for 1+3, enter 4.