THe mechanic for the disappearing scales is something like this:
Every province might get influenced by all of its neighbors scales (order, growth, prod). The more neighbors with a different scale setting the greater the chance of a change. Thus border provinces with low dominion will cause the neutral scales to spread until you have your dominion there to raise them.
I believe (but I'm not sure) that only provinces under your dominion will try to spread their scales to their neighbors, thus having a province with low dom might be worse than having one without dom, since the latter will not spread it's neutral scales around.
Also your scales will spread over your into your neighbors dominion if you have a stronger dominion/scales than he does. Always nice to help a friend
