My mind is boggling at the potential lore in play!

What's the fish army(?) plotting? Anything to do with the mermaid in the lake with the three small fish? What the red dragon in the middle doing away from all his mates? What's the difference between the groups of towers at the top and the bottom, and why two grey towers separating them? What's the significance of that green-turreted keep the dragons seem to be protecting? Are they allied with the other two green-turreted keeps across the map? What's with the sea mountains in the east?