There are multiple types of Sebilisian Trackers. 1) Scaled Wolf model 2) Iksar melee model 3) Iksar caster model
The wolf model will lead around multiple iksar mobs. If you kill the wolf model without aggroing the iksar models, they will warp to their spawn point and ramain static until a wolf tracker respawns and starts roaming again. I've seen a single wolf tracker leading up to 4 iksar trackers.
Their pathing seems truely random throughout their roaming area, and at times they can "track" you if you are just out of aggro range, following your every turn. Only by gaining distance will they lose your scent.