In that case why don't you just give all your opers ServicesRoot access? or appropriate access in OperServ? Would be far simpler.
All of them DO have that access. The problem is if they're not using the exact nickname. Maybe as a halfway point, it could be done that somehow Anope looks at the OPER name and not the nickname. So in my case if I oper as Trel, and Trel is a name listed in services root, I would be able to use superadmin even if my nick was maybe Trel[Away]. Currently unless there's some setting wrong, my nick has to be Trel as well.
better still, use http://modules.anope.org/viewmod.php?id=127 to make SET usable by Services Admins so you don't have to be root to use it. Then password protect it with http://modules.anope.org/viewmod.php?id=127 so only those that you want to have superadmin will have it. This solution conveniently works on almost all size networks.
That probably still won't work unless it tracks the nick changes. As in User_A could be listed as a service admin, but if he changes his nick to User_A[Playing_Game], unless it tracks that (and it might, I'm not sure), it wouldn't work for the same reason I have the original problem.
(Also, you gave the same link twice)