3 Systems
Wild Crane is actually 3 sysems operating together elegantly and ingeniously. It involves squeezing astrology and the 5 elements (or 5 paths, or 5 processes, as you wish) into the lines of the 64 hexagrams of the I Ching.
It is mostly an astrological system. The Sun is represented by the solar calendar, with its emphasis of the solstices and equinoxes. The Moon is represented by the need to expand the Celestial Stems and the Horary Branches into 12 parts (the Moon months). (The Stems are 10, but are sometimes represented as a circle of 12, the Earth parts repeated.) The 5 visible planets are misnamed "stars," tho practitioners would avoid explicitly identifying the "stars" as Mercury, Venus, Mars, Jupiter, and Saturn.
As an astrologer of many years, I regard this type of representational or symbolic astrology with little enthusiasm. By symbolic, I mean that, unlike normal astrology, no personal chart is being made here, plotting the actual horizon of anyone's birth, nor any particular event; nor are the planets (of which there are more than 5) plotted by their actual positions along the ecliptic. Instead, the zodiac and the celestial bodies are in this system symbolically, abstractly. This is more like the colours and numbers on a roulette wheel than actual astrology.
I will add that, although Venus (here on the right, with autumn and metal) could be roughly defined as spending money and sibling affection, I have never heard of Jupiter (here on the left, with spring and wood) being defined as anyone's wife. Mercury perhaps became associated with water and the winter solstice because it is so close to the Sun (seen from our perspective of the Earth) that is seems to periodically disappear, but astrologically Mercury is more specifically associated with the mail and any communication by print-voice-meeting than is Saturn (here the Earth and central).
Also, when the elements are arranged in a circle, like the zodiac, they form triangles, which Wild Crane defines as element combinations, just as they form oppositions (here referred to as "strikes"). But they also form "squares" every third element, as for example tze-mao. 90 degrees on the circle always represents energy combinations which are under great stress trying to accomodate each other and incorporate foreign ideas into the self's operations. You can understand this situation better if you ponder the major developments in your life during those years which were square to your birth year (for example, if you were born Year of the Horse, consider the Rooster and Hare years).
You can see something of this square issue in how the "empty" elements are listed 2 at a time on the right going up. The Celestial Stems (the Roman numerals I-X) go across the top, while the elements are listed in each vertical column from bottom to top (of the 6 hexagram lines), skipping one each time. The transition from one Stem to the next is by skipping 3 elements forward on the circle (a square). The only exception to this process is from I to II, because tze and chui are considered empty and invisible, so the count is from shu to hai, ein, and then begin again at mao. None of the other transitions from one numeral to another involves empty elements, so each vertical column stops at the top and begins again at the next bottom by skipping 3 elements.
As ingenious as this cooperative combination of 3 systems is, one can see why Wild Crane, being symbolic and abstract, is used mostly by people trying to gamble their way forward in life by a couple of dollars, whereas people who use the conventional Zhouyi text of the I Ching are after more profound answers (tho the thickness of the archaic text often defeats them).