In my impatience to begin GOTM 18, I've been playing the celts in a similar random pangea world. I set the barbarians on restless. With the PTW version, I've spent a lot of time fending off barbarians and have far more invested in garrisons than I usual. I expect Cracker's version will penalize thise who ignore his warning. The cool wet 4mm yr old world is very different from my typical game and city growth has been slow.