Did a quick Google and found out that Panglima is a district chief/leader and Datu is a tribal leader. The Sulu Sultanate was divided into five larger districts, each governed by a Panglima. So I assume that the order is Sultan - Panglima - Datu?
I noticed that there were five districts (five=lima), is this a coincidence?
In Swish of the Kris Panglima is translated as judge.
Michael
From
http://www.answers.com/topic/tausug-people
"...In 1390, Raja Baguinda landed at Buansa and extended the missionary work of Makdum. The Muslim Arabian scholar Abu Bakr arrived in 1450, married Baguinda's daughter, and after Baguinda's death, became sultan, thereby introducing the sultanate as a political system. Political districts were created in Parang, Pansul, Lati, Gitung, and Luuk, each headed by a panglima or district leader."