A lot of my drags have a wolf swivel attaching the chain to the drag, because I had them laying around and I needed to attach the chain to the drag somehow. And I don't like the big wolf swivels next to a trap to bed underneath it, even on wolf traps that come with them I have been replacing with welded crunch proof swivels. But in my opinion swivels more than three or four feet from the trap are unnecessary, that chain is usually tangled around brush anyways.

The obvious answer, should depend on your target animal . . . and just as important, the terrain.

Many trappers don't use chain that is heavy enough.
The longer the chain , the lighter you can get away with . . . although , nothing is 100 %.

Remember you have to pack it all in . . . and back out and the longer the chain, the more weight it adds to your pack.

* I have some High Plains Plows on 10 ft #2 twist link (welded) if anyone is interested,
( Should be at the NTA in Richmond.)