Garrisoning traders in merchant ship is not profitable

[mimo]

Garrisoning traders inside a merchant ship increases the gain by 20%, but I guess nobody ever used it as it has no interest. Taking the exemple of cart, we have trader cost = 100 food, 80 metal and time 15 s merchant ship cost = 100 metal and time 20 s such that building more ships is much more interesting.

There are several ways we could use to make trader garrisoning a better alternative:

• increase the price of merchant ships which anyway looks too cheap to me.
• increase the additionnal gain for each garrisoned trader.
• maybe increase the armour when garrisoned traders (more people to defend the ship)
• others ?

As a first step, I propose to increase the cost of merchant ships by 100 wood and increase the garrisoned gain from 20 to 40%.