OP was talking about putting 6" of dirt on top.
If the chickens scratch dirt off the pavers, they would also scratch it off hardware cloth. And I'd personally prefer pavers to hardware cloth, if one is going to be there.
Hopefully all the different opinions will help OP make a decision that...
I think the paving slabs sound like a better idea than hardware cloth. You could still pile dirt on top. No matter how deep the chickens dig, there will be no wire to catch their toes or your cleaning tools. Also, they will never rust out the way wire eventually will.