Also, the only thing about English silver or florins is that the precious metal content stayed pretty stable and English-speaking economic historians have a feeling of the kind of life different incomes in English pounds or florins brought and what portion of the population had that income. So its just a convenient money of account which lets someone whose specialty is say 13th century Florence or 15th century England have a feel for what the money means (and the florin was a pretty common money of account).
And the way big conscript armies tended to melt away or turn robber is one reason why so many princes wanted to cut deals with towns and cities to get the use of their militia, but that’s another story and you could talk about it all day.
