The wood discount is needed for the initial investment, otherwise it’s not that worth to use FT.
Yeah FT gives back a better wood-food ratio, but it’s a way bigger initial investment in wood, not only a FT cost 100w against a 60w farm, but you also invested wood into the fishing ships and docks.
The x3 food instead is to further incentive people using them. FT requires more management than farms, the ships cannot be garrison and anyway most people will end up with farmers anyway, simply because vills are more versitile and CNA better balance you eco.
From my point of view, you can’t remove the cost discount, or the initial investment will discourage most people from use FT, but you can’t neither make it big enough to get the same ratio of 32:1 food:wood, otherwise the initial investment it would become a joke.