In my campaign, I've established that civilized areas usually use paper writs as currency rather than coins, and part of going into town after an adventure is a swing by the local bank to offload those heavy coins. Part of this is that in the case of a treasure hoard, I like the idea of figuring out how to drag all those coins back to town.
This line of thinking, however, quickly made me realize that Karzoug, and by extension, his minions, are buying help using coins minted in the time of Thassilon. I'm thinking of making hidden perception checks when the players raid Thistletop, and later the clock tower, to notice that some of the coins they find look like none they've seen before. In fact, they have some Thassilonian script, and a Sihedron or rune of greed.
This wouldn't disrupt the campaign later, right? I think this small change may do a bit to help tie the first book into the rest of the story. Thoughts?
If you're asking if adding Thassilonian cultural symbols to coin treasures will disrupt the campaign... No, that should be harmless, perhaps even helpful. Some will depend on how much your pc's know about Thassilon (and how much you've permitted them to know) and how closely they monitor the details.
Who controlled the use of the Sihedron and Runes in the days of Thassilon? Was it okay to put them on coins? I don't know the "official" answer on that but given the frequency of their appearance in Thassilonian ruins (in this AP and elsewhere) I can't think of any reason they wouldn't appear on coins.
Giving the pc's access to those images might help them start to understand the rune names of Thassilon magic, sin magic, etc. And give them another information source besides a certain sage who can remain nameless.
