Randomized teams staying even?

This is my attempt at trying to make a function that gets all the players in the game and putting them on teams and making sure that even amounts of players are on each team. The problem is tho if another player joins after the game has started they arent put on a team and cant play till the next round. However, I want the new player to still be sorted into a team, without changing the current teams, just adding them to a team, keeping them even.

function getTeams()
	local teamNumber = 1
	repeat wait()		
		local lobby = {}
		local teams = {"Red", "Blue"}
		for _, player in pairs(game.Players:GetPlayers()) do
			if player.TeamColor == game.Teams["Lobby"].TeamColor then
				local character = player.Character
				if character and character:FindFirstChild("Torso") then
					table.insert(lobby, player)
				end
			end
		end
		
		local randomPlayer = lobby[math.random(1, #lobby)]
		randomPlayer.TeamColor = game.Teams[teams[teamNumber]].TeamColor
		toMap(randomPlayer)
		
		local lobbyNumber = 0
		for _, player in pairs(game.Players:GetChildren()) do
			if player.TeamColor == game.Teams["Lobby"].TeamColor then
				if player.Character:FindFirstChild("Torso") then
					lobbyNumber = lobbyNumber + 1
				end
			end
		end
		teamNumber = teamNumber == 1 and 2 or 1
	until lobbyNumber == 0
end