Boeing develops a minimum training model, FM, and MEL for each airplane it builds and sells. In the USA that becomes the starting point for the purchasing airline FAA approval to operate the model of airplane. The airline is free to add too, and modify the SOPs to fit their operations. The basic idea when seeking FAA approval is they may not make changes which are less than the manufacturer's.

Yes I have modified, developed and received approval from the FAA for new training programs, manuals, additions to the MEL list and SOPs. It is a process and quite frankly one which some airlines (and it would appear manufacturers) short cut to save money.

BTW I noticed good old Larry has changed his tune a bit. A whole lot less blame on pilot failure and now recognizing there is a problem with training and certification of their procedures.