This is retarded

[Ikonoclastia]

Trains are easy to explain.

A train is created by someone running from a mob, the mob keeps pace with the person or not far behind. As the person comes into range of other mobs the other mobs aggro and keep pace behind the person. As long as the mob is moving fast enough to keep inside the chase range of the person training then all the mobs will stick.

If the person is sowed and can outrun the mobs in any of those mentioned dungeons fast enough to get out of the mobs chase range on live then the mobs will stop following you.

Since the majority of players running from mobs won't have sow or be able to use jboots the mobs will usually all keep up until the person dies or they zone.