No you can't, Murph. It would be nice if you could, but it simply isn't true for a lot of parts. Even with the internet to help, you need the stock and the internal capabilities at the company to provide the parts your dealer doesn't stock.
I know Kubota shipped shipped stuff from Japan for my dealer in Vermont, but he admitted it could take weeks for some larger items. A large maintenance contractor I spoke to up by the University of Virginia a couple of years ago had just switched from Kubota to Kioti. He loved the tractors and his dealer, and clearly he'd gotten more for his money, but he commented it did take longer to get parts. The thing he'd just broken recently was some pipe that goes to the rear remote. They put in a temporary fix for him with a hose I think, just to get him up and running, but the part was on order. Compare that to John Deere over-nighting large parts from Georgia when a local farmer in Vermont needed his tractor fixed quickly, and it's not comparable. Deere has ability to get us parts faster.
The Deere company has more invested in their supply chain and stock, and we all pay for it (nix that, all Deere owners pay for it). I have freely admitted that this is not a valuable capability for me. It's likely not value added for kas either, but credit where credit is due.