I see a flaw here and it is to consider as coins the coins of those empires, something that would be more true in more modern times, but for example the Phoenicians began to use gold as currency and the Romans used coins of gold, silver and other metals, which were not worth so much for the faith that people had in them, as it happens today, as for the equivalence in weight of that metal. In fact, they began to inflate the coinage by removing a percentage of gold to introduce poorer alloys, which only worked for a short period of time, because as soon as people realized it, they began to give it the value it had in weight of gold.