Where should I set usergroups?

[MediCat]

Right now I have this code:

hook.Add ("PlayerInitialSpawn", "soc_set_sv_admin", function (ply)
	if soc.admin[ply:SteamID()] then ply:SetUserGroup("superadmin") end
	end)

and

soc.admin = {
	["SAMPLE_TEXT"] = true,
}

So ply:IsSuperAdmin() in this hook returns true, but if I request admin state later I receive false value. Should I put admin assignment code in another hook?

[editline]17th July 2017[/editline]

UPD. Solved, placed it in PlayerLoadout hook.