That's the problem really. The author, Paul Huges-Barlow, originally intended to write a book about the Opening of the Key spread, but somewhere along the line it transformed into something else altogether. It's all explained in the introduction.
His method is certainly based on the Opening of the Key with it's long strings of cards, but his pairing method is a little odd. He uses both elemental dignities and reversals at the same time! Using one or the other is fine, but to use both at the same time seems like overkill to me.
It's also most definitely not a beginners Tarot book. There's some fairly heavy material in there which is given the authors own spin, such as his unique use of Liber 231 LIBER ARCANORUM.