A team's leaderstat?

You could always just go through all of the players leaderstats, and add up the values. Given, that the player is on that certain team of course. Here's an example:

Team="Bright blue"
Plrs=game.Players:GetPlayers()

while wait(1) do --Repeats the process every second
    local TotalKills=0 --Sets the variable to add to
    for i=1,#Plrs do --Cycles through each player
        if Plrs[i].TeamColor=Team then --Finds if the player is on the desired team or not.
            TotalKills=TotalKills+Plrs.leaderstats.Kills.Value --Adds up the teams current kill count
        end
    end
    print("Total kills for "..Team.." team: "..TotalKills) --Prints out the total kills for the team
end

This would work good if you were just trying to print out the kills on a certain team. Anyways, this is just an example, so if you need any more clarification, please leave a comment below. Hope I helped :P