It's not the size of the hail necessarily, but also the wind velocity driving it.
The higher the wind, the more the damage becomes from the same exact sized hail.
Hail damage settlements, other than those exterior items that must be replaced, should always be stated by each individual panel.
In that way, should the same panel be damaged by collision, as an example, then the amount paid for the same panel for hail, can be deducted. That makes an insurance settlement fair for the company as it does for the owner.
Hail damage, or dents from the hail, most of the time, will almost completely disappear in time, simply from the heat of the sun and the coolness of the nights, but only on the roof and sides.
However, since all segments and quarter panels from 1969 to today, are a softer material than the roof and sides of Airstream and Argosy coaches, the hail dents in those sections, will rarely if ever disappear.
Many times I have gone back to the same owners living in "hail alley" year after year. I would show them the photo's of previous hail damage to their coach, that have simply disappeared. Seldom did an owner originally accept that fact, but as time went on, the word got out.
That made my job much easier each additional time that I visited them, for the purpose of settling with them for the new damages.
Should someone decide to replace panels, that were damaged by hail, they should absolutely keep accurate records that they have done so. In that way, should the same coach have another hail loss, a different approach to establishing the loss of value should be taken.
During my Airstream insurance time, I personally settled more than 1,000 hail loss claims, and as many as 24 of them in one day. But hey, I was younger then too.