Please remove Skaven corruption from the UI of non skaven players, it completely gives away the location of skaven settlements, which are meant to be indistinguishable from ruined settlements prior to investigation.The UI needs work anyway because you can tell that military units are present at a settlement in fog of war (UI states that public order is positive in settlements that the player cannot see. when you can see this number in the UI there is no number present).
In addition please add a % chance for skaven to spawn at and immediately occupy ruined settlements. This would ensure that you genuinely don't know if Skaven are there and whether or not you can occupya ruin. To balance this, it could take effect after turn 25 or so.