Sorry to say this but in your previous post your wrote:

"Aceh was in a ceratin time already really decentralised by it's own history. Again the Dutch at the highest thing only made use of a certain situation."

Now you say that "Aceh(I don't know about Negeri Sembilan)was not decenrtalised."

As for recent settlements, that is very much the pattern of Malay history throughout the centuries. New settlements springing up all the time. Typically, when a settlement became too large or a port silted up, a headman or prince would gather his clan and followers, go down the coast or river and set up a new settlement. This would either be in virgin territory or in an area previously settled but abandoned. It does not necessarily mean that allegience to the sultan or sovereign ceased everytime a new settlement was created.

What happened with the Aceh sultanate was that the Dutch chipped away at the subordinate magantes along the East and West coasts of Sumatra. They were given separate contracts, their caps (seals of authority) taken away and Dutch ones substituted. When Aceh proper was conquered 1879-1903, the sultanate was eventually abolished, and the "Teukus" who were closer to the centre were again given separate contracts within a new Dutch province of Aceh.

Once again, I would like to point out the fundamental difference between a treaty and a contract. The former recognises sovereignty, the latter does not.