Fairly common practice going back at least to the 17th century on broadsides. They usually appear on the front cover with 'or' in between.
The first name is the title most commonly used but sometimes if the second title is more succinct or occurs in the chorus it gets known by that name.

And you are not cluttering the thread at all. You are as usual adding much useful information for future researchers.

It would be good to put a date to some of his earlier songs that went into oral tradition. 'Jim the Carter Lad' is probably the most famous and appears in plenty of collections.