Hello,
First of all: Archion has protestant church records, Matricula has catholic church records.
And here a very short explanation about the Northrhinewestfalian church record situation, how I understand it. (Simplified)
Before the start of civil registration, every parish had to send a copy of their church books to the government. They are called "Zweitschrift" or "Kirchenbuchduplikat".
You recognize these record at familysearch as follows:
- they probably are called Kirchenbuchduplicat or
- in the catalog, there is a note "filmed in the Personenstandsarchiv ..."
- they end 1799 or 1875 at the start of the civil registration (the early date in the western parts that were under Napoleonic administration)
These you will not find at Matricula/Archion! They are kept at the Landesarchiv - a lot of them are already available online:
https://www.archive.nrw.de/landesarchiv-nrw/geschichte-erfahren/familienforschung/familienforschung-digital
(Of course there propably are records of the parish at Matricula, but thats a different version, covering a longer or shorter period, different naming of the books e.t.c.)
I only know the situation of the catholic original church books that were kept at the parishes:
The newer church books, that the parishes still need for reference, like bapticm certificates, are always kept at the parish.
The parishes can send their older church books to their diocesan archive. (But they also can decide to keep them).
Some diocesan archives publish the records on matricula, some have their own platforms.
And of course only church books earlier than the legally restricted period are published.
That is why you see places missing on the matricula map.
Some communal archives also keep (modern) copies of church books.
Best regards
Bettina