When placing a State Stake, it should count as the higher settlement type Available (Fed -> State -> Town). Right now. Its impossible to extend State influence, because they overlap.
Not only that, but i was able to create a Town culture building when i should be out of permission, Peculiar or Zen State should not be able to create culture buildings on behalf of Canal town!
If its working as intended, not only is not optimal, but also can be exploited.