I went back and counted....
the 'Beginning' NGW book has 8 or so basic tunes in the alternating-bass style(in addition to much other stuff)...
the 'Intermediate' NGW book has 11 or so tunes in the alternating-bass style....in addition the Intermediate book has 5 or so tunes that would be put in the category of walking bass as opposed to alternating bass (and again, this book, too, has much other stuff)...
These are tunes that are shorter (in general they are one-pagers) than what you will find in the 2nd Mark Hanson book.....in general they will be a bit simpler - quite a bit simpler... and more easily seen through to completion...that's a more specific reason as to why these books would make for very good additional practice...
Always takes me about 19 posts to get the main idea across