Complex sentence: In the north-south war since the Murle were mainly underrepresented and neglected by the SPLA, they sought protection by forming arm Group to protect themselves between the former rebel SPLA and the Northern Sudanese Militias.
Split into simpler sentences: In the north-south war since, the Murle were mainly underrepresented and neglected by the SPLA. They sought protection by forming an armed group to protect themselves from the former rebel SPLA and the Northern Sudanese Militias.