Drawing a square above every player in a table for nut script plugin

So here is the situation right now. I’m trying to create a squad system for nut script that will allow players to join squads. When a player is in a squad, a little green square will pop up above their head for their squad mates. What I’m trying to do with the script below is have a square pop up above players in the table alfa that will appear for everyone through the walls. But when I run the command, it doesn’t paint a square over their heads. I just want to know what to know how to fix it. It works if I replace the table alfa with players.GetAll() in the HUDPaint hook, so I can’t understand why this isn’t working.

alfa = {}

if CLIENT then
    hook.Add( "HUDPaint", "3d_camera_example", function()
        local ang = EyeAngles()
        local newang = Angle(ang.x + 90, ang.y, ang.z)
            for id, ply in pairs( alfa ) do
                local pos = ply:GetPos()
                local newpos = Vector(pos.x, pos.y, pos.z + 80)
                cam.Start3D2D( newpos, newang, 1 )
                    surface.SetDrawColor( Color( 100, 255, 100, 255 ) )
                    surface.DrawOutlinedRect( 0, 0, 4, 4 )
    end )

nut.command.add("squad", {
    onRun = function(client, arguments)
        if table.HasValue(alfa, client) then
            for k, v in pairs(alfa) do
                if v == client then
                    table.remove(alfa, k)
                    client:notify("You have left the squad.")
        elseif !table.HasValue(alfa, client) then
            table.Add(alfa, {k = client})
            client:notify("You have joined a squad.")