I have used a similar set up before Rob and there was no problem, especially on frost hardened (or sun baked!) ground.
The swivels will be a fine, albeit expensive in large quantities, addition to the snare, and they will make setting it up easier on the wire anchor pins
Edited to add: put the loop on your tealer on the other side Rob (towards the run) - that way the wire 'paperclip' will hold a double part of the loop and not pull out when it gets hit by something bigger
OTC