Monsters that are Chilled have the chance of being shattered upon their death which will leave no corpse to be raised. Monsters that are Frozen will always shatter when killed. Group Freezing spells can also quickly stop a huge army of monsters and break them up, making them easier to kill. Another trick for dealing with monsters that raise other monsters is to lead the minions or monsters around them away from the raising monster, which will generally stay in the same area. Once you've lead the minions enough distance away, kill them then go back to finish off the boss monster.
Some monsters have powerful ranged attacks but weak melee attacks.
If you rush up next to them, they will use their melee attack which may be far less damaging than the ranged attack they were using before. When in trouble, run. Run to another area if possible using dungeon doors, stairs, way points, and town portals to get away from the monsters. Melee characters should avoid being surrounded. Fight for a bit, then back away, to keep the monsters separated.