Well, between a meta of 1 civ, and a metà of 3 civs, I choose the one that is at least slightly better.
In my opinion, the problem of water meta goes beyond just civ balance. There are about at least 3 other civs that could be decent in water maps, but the meta is too much focused on 3 civs.
Yeah but FG don’t really threaten fishing ships, or doks, and can be countered by an equal number of your FG.
Fire galleys become important only in castle age, when they are upgraded into fire ships and you get careening. But here we are talking of feudal fights only.
Ironically keeping wheelbarrow/hand cart for vikings as a free tech but making it so that it is no longer researched instantly actually would make vikings an option on x256 maps without the vills bugging out.
I don’t think you nerf them without changes to water units themselves. If you nerf them, you’ll have another civ bonus become more important. Water is just a hyper-snowbally meta.