Phaeded: Two Pegasuses? You have not cited a single source for two such beasts. Of course artists are free to make up their own imagery, but Pegasus was a unique creation, tied to one birth-event with only one such horse. We've been over all this before, but I think the present discussion I can generalize to the CVI as well as the PMB.
The only place I know with chariots driven by two winged white horses is in the Plato's Phaedrus, the chariots of the gods and archetypes. I will give a few quotes from the Jowett translation on the Internet, so I don't have to type it out, even though it has some unfortunate wording (such as "through a glass dimly", which is not quite Plato's image). Since I am quoting without the context, I add some explanations in brackets. My emphasis.
...let the figure [of the soul] be composite-a pair of winged horses and a charioteer. Now the winged horses and the charioteers of the gods are all of them noble and of noble descent,... In the revolution [of the heavens] she [the divine intelligence] beholds justice, and temperance, and knowledge absolute, not in the form of generation or of relation, which men call existence, but knowledge absolute in existence absolute;
Few only [of the human charioteers[ retain an adequate remembrance of them; and they, when they behold here any image of that other world, are rapt in amazement; but they are ignorant of what this rapture means, because they do not clearly perceive. For there is no light of justice or temperance or any of the higher ideas which are precious to souls in the earthly copies of them: they are seen through a glass dimly...
The right-hand horse is upright and cleanly made; he has a lofty neck and an aquiline nose; his colour is white, and his eyes dark; he is a lover of honour and modesty and temperance, and the follower of true glory... Now when the charioteer beholds the vision of love, and has his whole soul warmed through sense, and is full of the prickings and ticklings of desire, the obedient steed, then as always under the government of shame, refrains from leaping on the beloved... And now they are at the spot and behold the flashing beauty of the beloved; which when the charioteer sees, his memory is carried to the true beauty, whom he beholds in company with Modesty like an image placed upon a holy pedestal.
And thereafter, for those who love in the Platonic sense:
After this their happiness depends upon their self-control; if the better elements of the mind which lead to order and philosophy prevail, then they pass their life here in happiness and harmony - masters of themselves and orderly - enslaving the vicious and emancipating the virtuous elements of the soul; and when the end comes, they are light and winged for flight...
It is easy to read the "they" here as meaning the virtuous charioteers themselves, rather than their horses. In fact that is how Ficino used the image (quoted by Frances Ames-Lewis in "Neoplatonism and the Visual Arts", Marcilio Ficino: his Theology, his Philosophy, his Legacy
, ed. Allen et al, p. 336):
Plato calls wings those [powers] by which the soul flies back to the heights whence it had descended...The soul can fly back with two powers, the contemplative and the moral...Plato means these two powers to be the soul's wings. [Footnote: Arthur Field, Origins of the Platonic Academy, pp. 181-82...).
So artists sculpting memorial images gave wings to the charioteer as images the soul of the virtuous deceased on his way to Elysium. Received opinion is that the image you showed is on the sculpture of a bust done to memorialize the death of one of Cosimo's sons, or maybe grandsons. Here is Wittkower's analysis ("A Symbol of Platonic Love in a Portrait Bust by Donatello", Journal of the Warburg Institute
, Vol. 1, No. 3, Jan., 1938):
Donatello's bust, conceived in the years of this first enthusiasm for Plato, can only be interpreted in a Platonic sense. It is inspired by the passage in Plato's Phaedrus [footnote: translated by Leonardo Bruni in 1423] in which winged genii on cars driving two horses with whips are described as symbols of the soul.
But there are no whips. Whips are for the soul in life, to tame the unruly horse. The cameo is of a funerary nature, showing the ascent of the soul after death.
In the tarot, the Chariot card is not among those after the Death card; it is in the company of the virtues. It is either the divine archetype of Pudicitia, seen by the soul before birth, or (if male) the Pudicitia-inspired charioteer in life (and with no whip because his unruly horse has been thoroughly tamed). There are two kinds of chariots: those with two white horses, representing the virtues, and those representing humans, with one white and one dark horse. It is fitting that the charioteer of the virtues, those with two white horses, be female. It is equally fitting that those of humans on earth be male, as Plato's unambiguously are. (No less than Leonardo Bruni had translated these passages, to the disapproval of some, and even he changed Plato by making Beauty female.)
Petrarch's second triumph is not that of Chastity, but Pudicitia, a virtue that applies to both sexes. The term can be translated as "sense of shame, aimed toward its avoidance", in other words, "honor". As a male in whom honor lives, the male charioteer is perfectly well suited to both Plato and Petrarch.
For female charioteers, the PMB and CY are not alone. There is also the Issy and the minchiate. That the Issy's charioteer is surrounded by four female attendants, seems to me to say that she is the Quintessence. And when art presented nude females, as we see in the minchiate version, they were acceptable and honorable to view primarily if they represented the ideal, and even then preferably if they showed a modicum of modesty (as Venus often did not).
calls the chariot card "the little world". That is as opposed to "World, that is, the father", i.e. the cosmic world of the B order's card 21. It is the little world of honor, reputation, and even glory during one's lifetime, as opposed to the glory (earthly as well as heavenly) that transcends death. It seems to me that there are also two Petrarchan representatives of Time: the short time of a life that can be cut short at any time, and the cosmic time of the heavens. And two Eternities: the eternal round of the Wheel and the cessation of all change when Time itself has been overcome at the Last Judgment.