As you can see Sarawak was at an expansion campaign . Yes Sarawak was an active invader on the Borneo island. By 1853, areas as far as Sibu were under Rajah Brooke's control. By 1861, Rajah Brooke controlled as far as Bintulu when Sultan Abdul Momin was forced to surrender that area as far as Tanjong Kidurong. By 1882 Baram. By 1884, Trusan and 1905 Lawas. SO LAWAS was part of Sarawak.
When Sultan Hashim took the throne, he took steps to preserve the rest of Brunei's territory. He tried to recover Limbang when Charles Brooke occupied it. Nevertheless, he was not able to do so and he did not manage to prevent further loss of Brunei's territories. Sultan Hashim did not have the military power to enforce the amanat. During those early years of his reign, Sultan Hashim faced the greatest difficulties. He faced pressure from Rajah Brooke and North Borneo Company.
In 1887, Sultan Hashim wrote to seek help from Queen Victoria imploring the British Government not to carry out the British plan's to subdivide Brunei further until the Sultan only govern the area of what is currently Brunei District.
When Sir Frederic Weld visited Brunei in 1887, Sultan Hashim called upon him to help protect Brunei. Sir Frederic Weld, the Governor of Straits Settlement, pointed out the best way the British can help was to have a British Resident advising Brunei. This led to the Protectorate Agreement between Brunei and United Kingdom in 1888.
Sultan Hashim agreed to sign the Agreement because he wanted to prevent further erosion of Brunei's territory. However, despite this historic agreement, the British Government failed to take any action against Charles Brooke for seizing Limbang in 1890. It was in 1889 when Charles Brooke insisted that Limbang be annexed to Sarawak. However, Sultan Hashim strongly opposed his demand.The British Government also refused to approve the ceding of Limbang. But Charles Brooke seized Limbang by force on 17th March 1890. So LIMBANG may indeed fall back to Brunei or we can form an alliance with Brunei to solve this problem.
Labuan is recognized as part of Sabah. Then given to the Federal government. If Malaysia ceased to exist hence there is no need for a federal territory. So Labuanese can held a referendum to be part of Sabah back or we make labuan a neutral state since it is located between 3 great Borneo nation i.e. .Sabah, Sarawak and Brunei