Your instinct about the Fool connection looks right to me. The Joker-Fool parallel runs deeeep, though historically they developed separately and the Joker came from Euchre in the 1860s, not from tarot like many assume.
I keep both in my Cartomancy deck, too. After years of reading, I’ve found the red and black distinction really matters. Red Joker tends to be that beneficial surprise, the risk worth taking, almost like the Magician’s energy. Black is more the traditional Fool - pure potential… but just watch your step.
The two-Joker situation gets… interesting. Sometimes they show up as polarities in the same reading - one pushing forward, one pulling back. Think of them as Spirit’s “wild cards”. They’re telling you the normal rules don’t apply here.
Some old-school cartomancers won’t touch them. My grandmother never used them. But traditions evolve. The Joker carries that trickster energy that’s been in divination forever, just in a new form.