Adopt NIST SP 800-82r3 to Your Architecture, Existing Controls and CSF Position.
Revision 3 runs past 300 pages and carries an overlay against SP 800-53. Read front to back, it produces reading notes rather than decisions.
Our personas cut it down to your case: which baseline fits, where the overlay tailors and why, how it reconciles with the CSF profile you already report against, and what to do first.
Adoption sequenced to your sites, not to the table of contents.