cope cages look like hardware fence (like chicken wire but welded, pig fence, sheep fence, goat fence are closer.)
However, the US already put fencing around fighting vehicles, specifically the Bradley, where the fence was essentially "chain link fencing".
I'm not entirely sure i buy that the cope cage stops drones; but the chain link fence absolutely stops RPGs from exploding by severing the wire that runs on the outside from the tip to the explosive.
Original cope cages were a very misguided attempt to copy the functionality of the actual working fence-like defensive measures. Except in those cases they did next to nothing, which is why they were dubbed cope cages.
AFAICT the concept was improved since then but I haven't been following the tech tree of cobbled-together defensive measures used in that war in a good while.