Stangle Khan
Warlord
Not necessarily, I mean the Indian UB adds +1 food on all farms (and +1 production on all floodplains). I'm not necessarily comparing farms to water-tiles, but I don't think the idea is that absurd.
Comparing for example a harbor with +1 culture on all water-tiles to the Songhai Tabya, which provides +1 culture on all river-tiles, on average the harbor is going to outperform it, but considering one is in ancient era building and the other is a Medieval era one I don't necessarily see that as that much of a problem. Especially considering culture is a lot more valuable early on.
That being said I'm not married to the idea or anything, so I'm totally open for better suggestions.
That's definitely true and it would give them even more impetus to settle on the coast. Also makes their UB much more useful long term whereas a bit of food or gold wouldn't.