we use one item such as articles of organization and our examiners were okay with that.
Just a suggestion. It is almost axiomatic that a corporation will have "articles of incorporation," an LLC "articles of organization" and a partnership a "partnership agreement" (yes, I know some do not). However that response is like saying an individual had a "drivers license," but not noting the number.
This comes from me, not FinCEN, but I suggest that when you are saying the entity had the document upon which its existence depends, you add the date; e.g. Articles of Incorporation DTD XX/XX/XX. It indicates you actually saw them. The "number" box might confirm that, but there will be none for entities that have no state registration; e.g. general partnerships, estates, trusts, etc.