hm ... I think, I described the idea already enough withrobert wrote: Nope. It's up to you to prove why they wanted 20. Just because the total adds up to 20 doesn't mean that that was the intention. Rather, the iconography seems to have been the intention, as it matches the rest of the standard group in theme.
Twenty is a nice number, (and it is very possible that that number seemed "right" for their aim, whatever that might have been), but there is absolutely no reason at all to assume they wanted "twenty" as a goal and chose accordingly.
Had twenty been the aim.. surely a group of twenty, five groups of four, four groups of five or two groups of ten would have been more appealing? Regardless, I see no reason whatsoever to assume that any specific number was important, rather, I see an expansion on a familiar theme. Prudence and the Theological virtues added to complete the group of virtues, the star signs and elements to enhance the last sequence of the standard tarot.
I assume, you know the Minchiate trumps. And I think, that you can understand the categories "older Trionfi" and "Florentine input, 20 cards, which changes the form of older Trionfi to Minchiate". So I don't know, which furtherhuck wrote:Further observation: the Minchiate is ordered in the following way:
1-15 ... a sort of "begin of older Trionfi"
16-35 ... a special Florentine input, 20 cards, which changes the "form of older Trionfi" to Minchiate
36-40 ... a sort of "end of older Trionfi", unnumbered
prove you desire.
Perhaps it helps, if you take a look at the article-series to ...
viewtopic.php?f=11&t=442
... Lorenzo Spirito and his "Il Libro delle Sorte"