[Unsolved] Is there a way of disabling the player list safely?

My game strongly relies on the concept of hidden teams. I therefore have to disable the playerlist, and as it is a local thing, I ask: Is there a way to disable the playerlist safely, without the danger of the players potentially messing with the local script and being able to see the teams?

There is! The method is way different from what you're thinking and works only on the client (i.e local scripts).

Local StarterGui = game:GetService("StarterGui")
StarterGui:SetCoreGuiEnabled(Enum.CoreGuiType.PlayerList, false)

For more information see: https://developer.roblox.com/en-us/articles/Disabling-Parts-of-Game-Interface

Yes, it is totally possible. Inside a localscript inside starterGui put:

game.StarterGui:SetCoreGuiEnabled(Enum.CoreGuiType.Leaderboard, false)