I believe so, and I'm referring to bronze coins (so pennies/low value). It's likely that there are just a slew of them as well. Rome existed for 1000 years and was developed and widespread. They would have travelling mints go along with the armies/expeditions and mint coinage on site. It winds up spreading to everywhere, hence the hoards found in the UK.

It may have been that less were melted down as well, Roman currency was good for a long time.