Page Size & Handling default settings differ radically to achieve similar print results between legacy .pdf files A & B, which creates confusion for customers. How can I update them for uniformity?

I'm working with several older legacy FrameMaker 11 (or earlier)-generated booklet-type .PDF files created by a former employee. Curiously, the Page Sizing & Handling default settings differ radically from .PDF file to .PDF file to achieve similar print results (2 document pages per 8.5 x 11.0 inch auto-Landscaped page), which creates confusion for customers. For example, .PDF file A is set up as Size/Auto-portrait/landscape, while .PDF file B is set up as Multiple (Document Size = 5.5 x 8.5 in) on an 8.5 x 11.0 inch page. Changing the settings on the Print page skews the output in the Preview window, so that page layouts appear out of order. How can these default values be updated to achieve uniformity in Page Size & Handling settings? From my review of the FM source files, Distiller Job Options and the legacy .PDF files, the answer isn't clear. Thank You in advance for any suggestions! (This question is also posted in the Printing & Prepress Forum.)