Dog with others that pretend to fight (6,6)

I believe the answer is:

shadow boxers

'that pretend to fight' is the definition.
(shadow boxing is pretending to box)

'dog with others' is the wordplay.
I cannot really understand how this works, but
'dog' could be 'shadow' (I've seen this before) and 'shadow' is located in the answer.
The remaining letters 'boxers' is a valid word which might be clued in a way I don't see.
This may be the basis of clue (or it may be nonsense).

I've seen this clue in The Guardian.

Want a hint initially instead of a full solution? Install my app