This modification would make the most sense if one believed that the basic G-M approach was promising but that the risks of either an untenable business model or high industry concentration, and consequent anti-competitive effects, were high. It is possible that a number of large, diversified financial holding companies would find an NFB a viable part of their operations.
G-M require that NFBs be stand-alone entities, and specifically prohibit ownership by commercial banks in an effort to avoid implicit contractual guarantees. This is a legitimate concern, to be sure, but one that might be at least imperfectly addressed through specific restrictions on relationships between affiliates in a bank holding company.