Like the sound of this bit from Eurogamer’s positive review:
Druids’ major addition is its trade system, which hooks into a network of ring forts you’ll capture and turn into upgradable, resource-building nodes. There’s a gameplay loop where you’ll discover a ring fort, clear it of enemies, then somewhat bizarrely hunt for its deed to officialise your trade and recruit a community of workers. From there, you can upgrade each fort further to improve output and store more goods. Each fort then sends their goods to Dublin, where you can flog them on to foreign cities. (Dublin acts as a sort of hub for this expansion, though mainly for the more mechanical bits and pieces you’ll do to earn rewards.