i usually just set a condition that casts movement restraints based on mobs hp
cond1=!${Target.MyBuff[mysnarespellthinggoeshere].ID} && ${Target.PctHPs} < 35 && ${Target.Fleeing}
the .Fleeing datatype is not super accurate, its basically just checks if the mob is moving and its heading is not in your direction, this could happen if the tank moves the mob too. thats why i check the low hp too.