Looking at the top of the life-tree of the first story:
3 Erinyen "revenge"
3 Hecatonchiren "100 arms"
3 Cyclopes "one-eyed"
Kentaurs have one eye and later they produce the lightnings of Zeus. What is one-eyed? The universe with a sun in the middle of it. A sun means "fire". "Lightnings" associate "fire". The Kentaurs associate fire.
The "100 arms"-figures appear very seldom in Greek mythology. They were "very strong" and somehow live near the "ocean".
They mean water.
The Erinyen result from blood falling on earth. They mean or present earth.
The early heaven (= fire) - earth - ocean (= water) - model is repeated in
Gaia = earth has children with Uranos (= heaven, fire) and Pontos (= ocean, water). Gaia is the central figure.
Also it is repeated in the 3 sons of Kronos:
Zeus lives on a mountain (Olymp) and means heaven and fire (lightnings).
Poseidon presents ocean and water.
Hades lives deep in the earth.
It's the Greek basic triade. Thales - the very first Greek philosoph, is known for the consideration, that "earth swims on the water", a natural idea, if one is a Greek, very well informed about the existence of enough islands and used to the appearance of earth-quakes. So the Greek model of the world puts:
heaven = above = Uranos, Zeus
earth = middle = Gaia, Hades
water = below = Pontos, Poseidon
Naturally this model is a little different from the Chinese triadic model. Chinese thinkers didn't have that much experience with islands like their Greek colleagues.
heaven = above
man = middle
earth = below
So returning back to the top of the life tree of he Uranos-Gaia-children, we can add the elemental qualities:
EARTH 3 Erinyen "revenge"
WATER 3 Hecatonchiren "100 arms"
FIRE 3 Cyclopes "one-eyed"
Later life-tree conceptions resulted in considerations like
--------- air ---------
water ---------- fire
***************
.... ------------- ....
-------- ..... ---------
.... -------------- ....
--------- ..... ---------
***************
-------- earth -------
Well, that was a problem of the later times, it was not the problem of the Olympic Tarot ... the poets had their own mind and one should accept this.
Interesting - especially in the elements question - is the poetical follow-up, that was given in the "after-Uranos-lost-his-genital"-story. Gaia had intercourse with Pontos (= Ocean) and got 5 children of him.
Nereus got 50 daughters, the Nereides and these do live in the water. Nereus = water.
Thaumas got Iris, Arke (a "bad sister" of Iris, who did fall to earth in the fight of the Titans) and the Harpiyen as children. Probably the "correct" number of the Harpiyen was 4, so he got totally 6 children - in the poetical calculation. All his children had wings, so it is likely, that Thaumas was considered to present the element air (although the basic triade didn't knew "air").
Phorkys married Keto - together 8 children and they produce the horror-figures of Greek mythology: 3 Graien with one eye and one tooth for all 3 together and the 3 Gorgons with snakes as hairs, then Ladon, a snake, who lives on the tree with the golden apples in the garden of the Hesperides (which has a very special mystery) and has 100 heads and 100 tongues, with which he can talk in 100 languages, and then Echidne, a fabulous woman, that had various other monsters as children, which created some work for all the coming heroes, who got a job cause of them.
It's unclear, which element-attribution was given to Phorkys-Keto, probably aither/fire or aither/earth.
Eurybia, the 5th component (elemental attribution is probably fire or earth) , became wife to Krios (one of the 6 male Titans) and from this she got 3 sons, but these sons do not belong the Gaia-Pontos-tree, as they are counted to the Uranos-Gaia-tree.
We've to return back to the Uranos-Gaia-tree ... the number of children was there: 22 ... and I called it a Tarot.
But I left two small aspects aside. Uranos had also some other sons, the Gigantes, and some "uncounted" Melian nymphs.
There were 24 "Gigantes".
How much "Melian nymphs"?
The "Gigantes" later tried to fight the gods and the gods could only win with the help of Heracles.
Who were the Gigantes, what do they stand for? Well ... the number of the Greek letters in the "new" Greek alphabet was 24. Still it is in use and it has 3 additional signs for using it also as number-system with 27 elements (1-9, 10 - 90, 100 - 900).
The Melian nymphs are attributed to the ash-tree and it was suspected, that early alphabets were connected to trees. Also it was suspected, that there was an alphabet with 18 elements. Ranke-Graves had worked on this idea.
If we assume ...
22 basic figures = somehow reflecting an order, that is connected to the Hebrew or earlier to the Phoenician alphabet (7 double, 12 simple, 3 mothers)
24 Gigantes = "new Greek alphabeth"
18 Melian nymphs = "older Greek alphabet"