The whole Germanic navy thing is an interesting question. I have also done the 6 warship, retrain over and over and slowly crush all. It is very expensive as they say- 5,400 mnai per turn roughly the cost of an entire good army, plus the very high costs of retraining. The savings I think depend, if you build advanced trading ports at Swebotraust and other cities then any blockade of a key port can cost maybe 2,000 per turn or so. So while conquering the pirates is prestigious, the 5,400 + retrains is IMO a bit hard to justify. Another cost-saver naval option is to just train 1 transport fleet, and leapfrog from port to port and sneak around the Jutland peninsula and finally secure a single ship in the port at Bagacos. From there one can do infinite army transports into Britain, still ending the ship's turn safely back in Bagacos. This way one invests the minimum in a navy for the maximum benefit of conquering the Casse and getting the druidic university at Ynys Mon, druidic healers are extremely beneficial for Sweboz generals.
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