Well, maybe you are right.
But C says (and we are playing C's game here, a game of guess the system) that 8 by one and 14 by another.
because the pairs need to be split.
Now, he is not clear about that.
He cannot mean that each pair had to be done one card by one artist and one by the other because the fool and the magician were done by the same.
He might mean (as I assumed) that all 8 by one artist would be used in the geomantic pairs (although as you point out, that does cause a contradiction with what he said the star being 'empty') or it could mean any number of the 8 were used, not necessarily all of them.
Now, thinking on that option, I'll stick with the sun for via, judgement for carcer and the star for caput draconis. I don't go for that empty thing...
But the two fortunas...
Minor would be the wheel.
Major would be.... hmm... What's left??? You're right, the tower, if it ever existed, is just a stupid idea.
I'll go for... the pope. On the assumption that back in them days if you got the popes blessing it was great good fortune to you!