I agree with you that polders appear fine from a balance perspective. In this I disagree with @Enrico Swagolo, who first raised the issue of Polders. I also agree with @Stalker0 in that, taken as a complete package, the Netherlands are an interesting civ. I do not agree with you or Stalker that this is therefore the end of the discussion. Yes, sapping 1-2 movement from enemy units would be fluff, but it would be historic fluff. There were several instances of the Dutch intentionally flooding the lowlands for defensive purposes, and even examples of occupying forces flooding the polders to cover their retreat. I'm not precisely sure what the adjacency on villages/towns is meant to be a callback to, but the defensive use of polders seems the most salient aspect of their historic value. If the adjacency bonus were dropped in favor of it I think it would be an improvement. What would be required is adding an exception to MovesChange so that units on roads or that ignore movement penalties aren't affected.