How to change player's rank according to player's team?

I've been trying to make a script that changes the player's rank on the leaderboard according to the player's team. It uses group IDs and role values to change the player's rank accordingly. So for example, if my team was "Army", the script would grab my rank from the group and change my rank on the leaderboard according to my rank in the group. If I was switching from the "Army" team to "Marines", the script would grab my rank from the Marines group and change my rank to my rank in the Marines group.

Here's what I got, I don't know why it's not working:

local playerStats = {}

local TeamsService = game:GetService("Teams")

game.Players.PlayerAdded:connect(function(player)
    local leaderstats = Instance.new("Model", player)
    leaderstats. Name = "leaderstats"
    local grouprank = Instance.new("StringValue", leaderstats)
    grouprank.Name = "Rank"

    local teamName = "Civilians"

    for _, team in pairs(TeamsService:GetTeams()) do
        team.PlayerAdded:connect(function(player)
            print(player.Name.. " has joined " ..team.Name)
            if teamName == "Army" then
                local rank = player:GetRoleInGroup(165491)
                if rank ~= 0 then
                    grouprank.Value = rank
                else
                    grouprank.Value = "Guest"
                end
            end

            if teamName == "Marines" then
                local rank = player:GetRoleInGroup(4187067)
                if rank ~= 0 then
                    grouprank.Value = rank
                else
                    grouprank.Value = "Guest"
                end
            end
        end)
    end

    playerStats[player] = leaderstats
    player.TeamColor = game.Teams[teamName].TeamColor
end)