It would have been helpful to survey the alternatives, and while I know that the (very nice) book by Raymond Anderson has a different style and is not a competitor, and the book by Naeem Siddiqi has uninspiring reviews, I cannot access the two books co-authored by Helen McNab. Steven Finlay's book looks solid, but largely "nested" by the combo of "Consumer credit models" and the 2002 book by Thomas, Edelman and Crook - which, I believe, jointly capture the domain knowledge available in book form.
This book is the kind of book you need when you start in a particular field of business or have been there for a while and need to remind yourself why certain things are done in a certain way. The author starts out with first principles and builds on the basics to cover every application and all the key alternative approaches.