Can you tell me where in admin cp you're finding that? I swear I do not have those options. I am running 3.5.0 I'm in AdminCP > Usergroups > Usergroup Manager, then editing Super Moderator permissions. Even vBulletin said there weren't permissions for that for super mods. Are you sure that isn't a hack?
As said, you need a Hack for that: Restrict Supermod Permissions
I think that would be better than just removing the link, as they still could access it.