The coin mechanic is very similar to the artifact mechanic, and arguably worse. Coins can be hoarded just like points in artifacts with Order ability, and then used all at once with different units (on deploy) for big swings, and that multiple times, similar to artifacts. For the opponent, there's nothing to interact with, not even on a binary level like artifacts. And that's not fun, not fun at all. So let's change that, because coins are actually very cool.
Instead of saving coins in one general pouch at the leader, let them stay with the units that provide or create coins. These units will have a pouch icon with the number of coins they hold. When they have coins, they can give these coins to other units who have an ability to use coins. A unit that kills a card that holds coins will get the coins from that card and can give them to another unit. This way coins can flow across the battlefield. Units who hold coins are at risk for being targeted for extra value and need to be strong or protected somehow. I think this would be a very fun and highly interactable mechanic with lots of possibilities in combination with existing mechanics. New cards for all factions may use coins as well, especially the new Novigrad: Guilds expansion I proposed in the "What's Your Opinion of the Syndicate Faction? [Poll] " topic.
Instead of saving coins in one general pouch at the leader, let them stay with the units that provide or create coins. These units will have a pouch icon with the number of coins they hold. When they have coins, they can give these coins to other units who have an ability to use coins. A unit that kills a card that holds coins will get the coins from that card and can give them to another unit. This way coins can flow across the battlefield. Units who hold coins are at risk for being targeted for extra value and need to be strong or protected somehow. I think this would be a very fun and highly interactable mechanic with lots of possibilities in combination with existing mechanics. New cards for all factions may use coins as well, especially the new Novigrad: Guilds expansion I proposed in the "What's Your Opinion of the Syndicate Faction? [Poll] " topic.