[frankie_t]

There is a parallel to this Celtic imitations that is found primarily in modern Ukraine[1], attribute to Cherniakhov culture[2]. The theory for them is that once the trade with Roman Empire ceased, the locals needed bigger supply of coins and started minting their own.

There is a curious thing with this "branch", I'm not sure if it's the same in the Celtic one. The last time I talked to people researching this, I was told that: a. The findings are mostly unique, it's hard to find two copies of the same coin. Sometimes obverse of one coin could be found on another, but reverses don't match. b. These coins are not cast, they are minted through "hammering", which requires a stamp. However, not a single stamp has been found so far. A much easier way to make currency out of existing one would be to just slap existing coin into some clay, make a casting mold and just pour molten metal into it.

This of course is more of a curiosity/rumor level, I don't have any qualifications to back it up.

[1]: http://barbarous-imitations.narod.ru/ (apologize for a .ru website, but it's the best catalogue to my knowledge.)

[2]: https://en.wikipedia.org/wiki/Chernyakhov_culture

[xyzzy123]

I feel like the religious explanation is a copout (the rest of the details are in the spiritual realm lol) and maybe there are practical ones.

Like maybe coins are rare enough that they're not completely fungible, there is a slight preference for being able to know which one is which?

Say, people want to have affordances to trace the provenance if that starts to matter.

It could also be a legitimate aesthetic preference for currency units to be unique rather than uniform.

Maybe uniformity is hard but why make the dies much bigger than they need to be and use different parts?

Striking is downstream of casting, technologically because you need to make harder things and perform extra steps to do that.