The checklist itself is a table of contents. All your forms, and accompanying evidence should be ordered in the same order as listed on the checklist. Nothing more is required.
That said, I made sure that for long answers to questions on some forms that were typed on a separate sheet of paper that the page or pages were clearly marked with the Principal Applicant's full name and date of birth, the Sponsor's full name and date of birth, that it was a Spousal application, and exactly what question from what form the typed information was being answered.