Complex sentence: Song Laosheng, who may have seen this as an opportunity of destroying his enemy piecemeal, deployed his army outside the town wall, but proved reluctant to advance further, and had to be goaded further away from the town through a feigned retreat by the cavalry.
Split into simpler sentences: Song Laosheng, who may have seen this as an opportunity of destroying his enemy piecemeal, deployed his army outside the town wall. The Sui general still proved reluctant to advance, and had to be goaded further away from the town through a feigned retreat by the cavalry.