This is intriguing. I've only played one deity Netherlands game, a while back, and yes, it did go well. But the map was pretty good (admittedly I re-rolled until I got a desert start, it also had a meandering lake allowing for several FPs), but I attributed the ease of victory to the map more than the civ. Breaking them down, it doesn't seem like a whole lot on paper. The UA is well above average, certainly one of the more underrated UAs on the forum, with a few different tactics to use with it, but it certainly isn't in the league of Ingenuity or Solidarity. Polders make for some high yield tiles, but there's three problems with them: 1.) availability. Only allowed on marshes and FP's, which are low frequency tiles. There's also the consideration regarding marshes of whether to have an unusable tile until guilds, or permanently remove the ability to make a polder there. If this is one or two tiles, you obviously keep them, but if there's 7 or 8 of them in your cap's 3-ring, it seems pretty costly either way. 2.) Maturation time: guilds isn't a late tech, but you're probably about 100 turns in before they're available, and the first 100 turns is pretty critical. Even then, the marshes just become 4 food tiles, no different than a flat, wet farmed grassland, and FP's are that plus just 1 food. It isn't until economics that they become super yield tiles, and quite a bit is decided by then. 3.) Oil/uranium - these are often revealed in grass/marsh tiles, and forces a tough decision... Well, it's not that tough. Sacrificing the polder enables hooking up the oil, and oil is just too powerful. As mentioned above, polders only really shine after economics, and the player would prefer a broader window of opportunity than between economics to biology.
The UU is so-so, navigation unlocks privateers and frigates, and the focus is obviously on frigates. Another consideration is that players often prefer to play Netherlands on Sandstorm maps to maximize polders, but this has little to no area for naval battles.
This is not to say that they aren't good, just that aren't an overwhelming choice on paper. Emphasis on "on paper," there's some civs that don't appear to have a lot going for them when evaluating their bonuses, but are better than they seem in practice, and this may be the case with the Netherlands. A primary example of this is the Shoshone, since I play without huts. It would seem that without huts, I lose the biggest part of their advantage and they'd be a bottom tier civ for me. However, starting with the extra land is such a big bonus, one often overlooked by Shoshone players who go hut-hunting. Often means that you'll have 4 or 5 "3 yield" tiles that are unimproved. It's a significantly better tile bonus than America or Russia since they're free rather than discounted. Finally, there's incredible compatibility between the two components of the UA - you get more land, and you get a combat bonus within your (expanded) lands.
