Side question:

I'm surprised by the explanation of the 8 in the "real de a a ocho" because "traders counted gold doubloons on their fingers, skipping their thumbs." (and the link to investopedia has a similar explanation).

But from https://en.wikipedia.org/wiki/Doubloon

> Spanish American gold coins were minted in one-half, one, two, four, and eight escudo denominations, with each escudo worth around two Spanish dollars or $2. The two-escudo (or $4 coin) was the "doubloon" or "pistole", and the large eight-escudo (or $16) was a "quadruple pistole"

I think it makes more sense that some time ago it was possible to split some coins in half and quarters, so someone decide to continue the tradition and use base 2 to move up.