The question isn't who works harder, but who is properly compensated for their work. Answer, not FedEx and definitely not FedEx Ground.
All of us work hard, and I would be the first to say that mental strain can be just as hazardous to your body as physical strain. With that said I too drive over 160 miles a day, deliver 150 to 175 stops and then must do some back tracking to cover pickups. However I have made over 100K in 2 of the last 3 years and have awesome benefits and a pension to focus on. Is it a trade off? Absolutely, but at least I'm compensated for my labor.
FedEx employees need to stand up for themselves, maybe the union would come in if they really thought they had a chance. I do not know for sure but charity starts at the front door.