I hope you don't spend too much money, Max, as the theory of assigning elemental, planetary and zodiac qualities to the trumps is very simple to explain.
The Golden Dawn Tarot Zodiac associations are based on the Sepher Yetzirah Hebrew alphabet correspondences, which are then assigned to their respective Tarot trumps.
The Sepher Yetzirah (SY) divides the Hebrew alphabet into three kinds of letters: three “Mother Letters” (Aleph, Mem, and Shin), twelve “Single Letters” (Heh, Vav, Zayin, Cheth, Teth, Yod, Lamed, Nun, Samekh, Ayin, Tzaddi, Qoph,), and seven “Double Letters” (Beth, Gimel, Daleth, Caph, Peh, Resh, Tau).
The Mother Letters are so called because in the SY they refer to the three elements Air, Water, and Fire, which give birth to everthing else (symbolized by the rest of the alphabet) in endless permutations.
The Seven Double Letters are so called because they have two sounds, a “hard” and a “soft” sound, for instance Beth can be pronounced as “b” or “v”. The SY refers these to the seven planets.
The Twelve Single Letters are so called because they have one sound, and the SY refers them to the signs of the Zodiac.
Thus, when the Tarot trumps are assigned to Hebrew letters, they can also be assigned these elemental and astrological qualities. This results in the following Zodiac scheme for the traditional or Tarot de Marseille order of the trumps -
Heh=Aries=Emperor
Vav=Taurus=Hierophant
Zayin=Gemini=Lovers
Cheth=Cancer=Chariot
Teth=Leo=Justice
Yod=Virgo=Hermit
Lamed=Libra=Strength
Nun=Scorpio=Death
Samekh=Sagittarius=Temperance
Ayin=Capricorn=Devil
Tzaddi=Aquarius=Star
Qoph=Pisces=Moon
In the Golden Dawn scheme, it is straight serial reading from Heh-Aries-Emperor to Qoph-Pisces-Moon. There is one exception, based on the Order’s founding document, the Cipher Manuscript, which switches the two cards in their traditional order with Justice at Teth and thus Leo, and Strength at Lamed hence Libra. The cards switched Hebrew letters and adopted the Zodiac attribution of the letter, so that Strength is now Leo and Justice is now Libra, in the Golden Dawn order.
Crowley also switched two Zodiac cards, Heh=Aries=Emperor and Tzaddi=Aquarius=Star, but in contrast to the Golden Dawn switch, the cards kept their Zodiac attribution when changing places. Thus, in Crowley’s scheme, Heh=Aquarius=Star and Tzaddi=Aries=Emperor.