Hello,
Internally, DOCX documents work with section not pages. A section can include headers and footers (default, first and even); and each section can fill one or more pages (or even a page can has more than one section) when the document is opened (using MS Word, LibreOffice, OneOffice, Google Docs...).
You can use removeWordContent to remove specific contents in a DOCX, for example the existing headers in a specific section.
Regards.