If I need to provide the actual e-mail, I can. Steve Shaw responded to that exact question and replied, yes, if Team A has 5 linemen numbered 50-79, they can shift all they want, because the rule is all about numbering EXCEPTIONS, and, if they have 5 linemen 50-79, there are no EXCEPTIONS, so they can assume whatever formation they want, as long as they maintain the 5 linemen numbered 50-79.