Allusion in Judges 18:20-29

Judges 18:20 Taking away a teraphim
Judges 18:21 Depart with little ones, cattle and carriage before them
Judges 18:22 People chasing them
Judges 18:23 Asking why so many people chasing them
Judges 18:24 Being asked why they steal especially the teraphim
Judges 18:27-28 Kill all the people in a city

Genesis 31:19 Taking away a teraphim
Genesis 31:23 People chasing them
Genesis 31:26-30 Being asked why they steal especially the teraphim
Genesis 31:36-42 Asking why so many people chasing them
Genesis 32:16-22 Depart with little ones, cattle and carriage before them
Genesis 34:1-31 Kill all the people in a city

They were not placed in exact sequence, but a number of essential elements were in common. Certain rare keyword like הַתְּרָפִֽים can be found from both cases as well.

To explain such an allusion, I would say that the two stories at the end of Judges were indeed trying to conclude that Israelites were not doing well after they arrived Canaan. And in order to show that the specific problem of Dan is indeed general to the whole Israelites, the author was trying to allude the bad deeds of Dan back to their very ancestor Jacob. As a result, the specific issue of Dan was shown to be rooted from Jacob, this allusion serves to make specific example to general problem of the whole Israelites.