I believe that if I were going to the expense of having the trailer painted and clearcoated, that I would have to agree...a few painted on graphics of your own design and color scheme before the clearcoat would be the way to go. I've seen some plain white "FEMA" looking trailers where the owners have taken off all the graphics and logos and, to me, they look lacking in something...flair, for the lack of a better word.
Granted, some companies tend to over-do the graphics, a few graphics can hide a lot of dirt by drawing the eye away from the huge "blank white canvas" of a plain jane exterior. As a trailer ages, the plain white tends towards yellow and some splashes of color tends to hide that aging process a little longer. An older 5er just left the campgrond we're in and it looked just that; old, well maintained, but, old. An equally older 5er next to it had some graphics on it that draws the eye and while be about the same age, it looked years newer.
A big advantage to having some new ones painted on, you can "individualize" your trailer, keep to colors that appeal to you and add as many or as few as what appeals to you and you alone and painted on, they should hold their looks for a lot longer than decals.
My 2 cents, your mileage may vary...
2 Cats; J-Lo and Ragamuffin :R
2014 Thor Tuscany 40RX DP
2011 Ram 2500 Longhorn CTD HO
2011 Keystone Cougar 318SAB (now gone)
2008 FunFinder X 210WBS (Sadly gone)