Hey @Kyle Doney. A promissory note is the contract between the lender and borrower, it references the transaction and deal terms; the mortgage, or deed of trust, is the security instrument that puts the lien on the property when recorded properly.
Different lenders have different documents for their various loan types and lending practices. Moreover, when private or specialty lenders do for example business-purpose loans on non-owner occupied property certain disclosures and documents aren't required. Lenders in this space tend to create their own form docs in order to sufficiently protect themselves.
Title company has a certain set of docs, this usually pertains only to the Title Policy on the property.
The deal does drive doc preference as do state/federal statutes/regulations.
We tend to give certain disclosures that are not required but feel they help educate the borrower and also make clear what is expected of the borrower and owed at closing or at maturity.
Really the documents vary and you are correct in opining that the deal does drive doc preference as do state/federal statutes/regulations.
Regardless of how helpful, clear, or informative a broker or lender is, I would think it's best to have local counsel review the closing packet.
(This is not legal advice, merely my opinion.)