Yes, the account you linked to of Ganjifa is quite parallel to Levi, with a suit of slaves in one game and a "major" card called the slave in another game, the lowest after the King and Queen. That makes a good case that Levi was drawing from an article of the time about Persian card games. The only problem is that of finding a source before 1860. Travelers' reports said that the deck was 96 cards in 8 suits. That makes 12 cards per suit.
Islam in India has number cards Ace to 10. So we don't know when the "slave" became part of the deck (as opposed to the 10, which might have been added instead).
I was focused on your other idea about a relationship to "jack-slaves" in Shakespearean English. That idea seems dubious to me, because "esclave" did not, as far as I can find, have an equivalent meaning of "rascal" in French, nor was it applied to the jack in playing cards in France before Levi.
In support of your idea (of Levi's having read about Ganjifa) is that Christian's astrological tarot identifies the kings of the tarot deck (he calls them masters) with four "royal stars" in Leo, Taurus, Aquarius and Scorpio (see
Histoire de la Magie, pp. 495-496, at
https://gallica.bnf.fr/ark:/12148/bpt6k ... /f515.item and following). Francois Arago had written about precisely just such "royal stars", attributed to a Persian source, in his
Astronomie Populaire, published 1861, which repeats information from another book of 1822, first published 1794 (
http://articles.adsabs.harvard.edu//ful ... 9.000.html and preceding). You can read more about the Royal Stars in Wikipedia's article by that name.
What (
Islam in India says about trumps in the first game he describes (p. 335) is very interesting: "The major cards in each suit are trumps." That is similar to how I interpret Marziano's game of "deified heroes", c. 1420, and "VIII Imperadori" (of which only the name is known but which I interpret in light of other games by means of "informed speculation"). It also goes 10, 9...Ace in the major suits and Ace, 2...10 in the minor suits, which is similar to Marziano's game. I also see that it was not prohibited by Islam, unlike a purely gambling game.
I wonder how far back these rules go. According to Wikipedia's article on Ganjifa:
The first known reference can be found in a 15th-century Arabic text, written by the Egyptian historian Ibn Taghribirdi (died 1470). In his history of Egypt he mentions how the Sultan Al-Malik Al-Mu'ayyad played kanjafah for money when he was an emir
I cannot imagine that the idea of the major cards (i.e. courts) being trumps would have been a modern result of European influence, because I don't know of any modern games in which this is true.
Islam in India also says that "spades were always trumps" in the second game (p. 336). That could be a result of European influence, or vice versa, although I don't know of game with that particular rule, in which a regular suit just like the rest is a permanent trump suit. Given that the Near East and Central Asia had cards before the Europeans did, perhaps they had games with permanent trump suits before them, too.
This game, Islam in India says, was a three-handed game, each person for himself. That is how I think
trionfi was, too.
Thanks very much for the link to
Islam in India.
Added a few minutes later: I changed the first paragraph slightly after rereading the Wikipedia article more closely.