I noticed that on virtually all maps with water and land, it is a great disadvantage to not build a Dock as soon as possible.
This is because the Dock essentially doubles the amount of resource collecting entities (RCE) you can create.
This leads to a certain build order that is difficult to escape from.
To make things more interesting, it may be beneficial to reduce the efficiency of fishing ships during the Dark Age.
This could be done by decreasing the collection rate by 25% and the carry capacity to 10.
In the Feudal Age, the fishing ships would automatically upgrade to their current state.
This would result in a stronger economy for those who chose to build the Dock, but they would do so later than if they had not gone with water.
This would also make Nomad more varied, as not building the Dock right away could be a viable option.