Network Admin – clone to new role

I have a multi-site installation and i need to give 2 people network admin access but control their menu options, i have plugin for managing the menu,but if i apply it to super user it also applies to my options, i need to create a user role with the same settings but a different name.

I have

add_action('admin_init', 'cloneRole');

function cloneRole(){
    global $wp_roles;
    if ( ! isset( $wp_roles ) ){
        $wp_roles = new WP_Roles();
	}

    $adm = $wp_roles->get_role('super_admin');
    //Adding a 'new_role' with all admin caps
    $wp_roles->add_role('alt_super_admin', 'alt Super Admin', $adm->capabilities);
}

which adds the role but does not give super admin capabilities, is there another option?

TIA