Ranger Smith,
Length pretty much determines a tag axle or not.
You will not wear out tag tires, replacement will be required way before they wear out.
When driving over speed bumps, you don't bounce going over as the tag takes the down motion softening the bump.
Also, if for some reason you have unusual wear on the front tires, you can take the tags and put them on the front. We did that when we had a bad alignment on our previous coach (42 ft.).
Another thing to think about, all Winnebago's have rear radiators, a side radiator would be at the top of my list.
Safe travels and good luck!
MM.