Hi Karen,
For the churches in Württemberg, I can only speak from my own experiences:
Beginning in 1808, in addition to baptisms, marriages, and burials, "family registers" had to be kept by the pastors. You will find standardized family registers for all churches on printed forms in books.
In the beginning (around 1808), pastors often tried to add new entries in alphabetical order by leaving blank pages. But as the pages filled up, they had to abandon this order and put new entries at the end of the book.
Later, the family registers were filled chronologically in the order in which new entries had to be made (not in alphabetical order).
A new entry in a family register was created when a couple married. Or when a couple who had moved to town had another child. Or, occasionally, when a family moved into town and the pastor took the new residents to the family register to add baptismal or burial records to the family register.
In other words:
You will find all couples married after 1808 in a family record. Those who were married before will only be found if they had children after 1808. Or simply when a pastor wanted to have all his local families still alive in his Familienregister...
Before 1808 in some places there were "Seelenregisters" for different purposes and with different looks. Some of them are similar to the Family Records.
In your case, you will find Johann Georg Matthes, b. 1761, married 1784, on page 294 in Kupferzell:
http://www.archion.de/p/02533a10c8/ (brother of "your"Johann Friedrich Matthes b. 1769?)
According to this, his father was Johann Michael Mathes, Hofbäcker in Kupferzell. Please note that there is no refferring page number with the father's name, so you will not find an entry in this Familienregister.
Due to the absence of Johann Friedrich Matthes in this Familienregister it is likely that he probably had married and moved to another town.
Or he stayed in Kupferzell and never got married. To check this, you will have to search all other Kupferzell church books for him.
Kind regards,
Michael