It sounds like you need some new tire wear experts. Wearing on the outside edges is a classic toe adjustment problem. The fact that both front tires have the problem and none of the rears have the problem suggests it was never aligned properly when when the completed motorhome left the factory.
Ford recommends a front end alignment with the motorhome fully loaded with everything you normally travel with. That includes fresh water, propane, fuel, food and any personal possessions you normally take.
Ford sells the stripped chassis to the motorhome manufacturers. The manufacturer then adds several tons of house, appliances and systems. Depending on the weight distribution it can have an effect on front end alignment.
For nearly 30 years Ford has recommended having the front end aligned when the vehicle is completed. Most manufacturers come close, but don't do a very good job at it. There have been a couple Ford technical bulletins on the subject over the years. The problem got so bad in the late 1990's that Ford issued Technical Service Bulletin Q-59 "Clear Vision TSB" It outlines the procedure for aligning the front end and centering the steering wheel. It also includes a paragraph stating Ford will no longer warranty tire or other damage caused by a misaligned front end. While the procedure for straightening the steering wheel has changed in the last few years the alignment procedure is still the same and is still required.
We have the same Michelin tires on our 2013 Adventurer. It was aligned at our local Ford truck dealer with about 300 miles on the odometer. It now has over 33,000 miles on the odometer with no signs of excessive wear on any of the tires.
As a side note I would stick with the Michelins unless you can watch the mounting and balancing process when the Goodyear's are installed. Let me say at this point I had always been a Goodyear fan. Over the years we've had a couple dozen sets on our cars and trucks without any problems. However the G670's were another story. We had 3 sets of G670's on our previous Adventurer in 115,000 miles. The first set lasted only about 30,000 miles. They vibrated constantly and could never be balanced to the point the vibration would go away.
The second set didn't last much longer. They were supposedly balanced with Equal balancing powder when they were installed. They never did seem perfect so on one of our trips I stopped at a tire dealer to have the powder removed and conventionally balanced. That's when we found the balancing powder had never been installed. The worst tire now needed over 12 oz. of weight to bring it into balance. The other tires took between 6oz. and 10 oz. to balance them. The tires went about 45,000 miles, but the ride was never much better. We finally replaced them, not due to being worn out, but rather due to the poor ride quality and constant thumping from flat spot worn on them due to improper balance when they were new.
Being a slow learner we replaced them with another set of G670's while the ride was better it doesn't compare to the ride quality of the Michelins on our current motorhome.
Be careful to check the manufacturing location if you choose Goodyear's. The last set I bought for our truck were made in China. They're advertised as being 50,000 mile tires. They currently have about 15,000 miles on them and I doubt they'll make it to 30,000 at the rate they're wearing. Over the years the quality has certainly slipped as has my confidence in their products. I have gone from a total die hard fan of Goodyear tires to wondering what I should buy the next time one of our cars' or trucks need tires
Hikerdogs
2013 Winnebago Adventurer
