Just let the ferals be ferals in their natural habitat.
Just don’t let them become an invasive species.
If they were cats we would take them in and have them neutered or spayed. Maybe Mike Tyson could bite off a little piece of their ears.
I agree. Build a tall electric fence, keep them in and let them kill each other off. Remove the fence, high pressure wash the mess and bulldoze it away. Start over.