Have you noticed how good is the sea/river merchants? I mean, I knew they were good, but man, if you spend in 3-4 of these boats in feudal you will have enough gold to get into imperial while you research most of the technologies.
I usually play with a friend in megarandom mode, and everytime we spot a river crossing the map, we put docks in each side, and enjoy.
A merchant ship costs 300 wood 100 gold, and in the first return they come usually with 300-500 gold and 200 wood approximately in large routes.
Usually I end up with 6-9 of these ships, and 10 villagers in gold, and the rest 2/3 in food and 1/3 in wood, and reach imperial so so fast, with tons of resources.
The risk is getting attacked in feudal, because you are spending a lot of wood in merchant ships, but if you pass to castle, you can spam technologies and start to get an army and hostigate enemies.
What do you think about these ships? Are you used to put them everywhere?
Usually they are in a risky zone of the map (eg. a river crossing the middle of the map), but if you manage to defend the river and avoid the enemy to put towers, is ez economy.
In my rank (gold-platinum), even players doesn’t pay to attention to river ships, until it’s too late.