Ok so a roller is what about 3" wide... And the boat sits on what...maybe an inch...so 3 sq /in per roller.
A basic stand pad is what 12" x12" or 144 sq/in...so you would need about 48 rollers to equal the spread of one pad...
A basic bunk is what, a 2x6?, probably 8' to 10'...?
Let's use an 8' bunk, 96" x 5 1/2" or 528 sq/in times two (one each side) or 1056 sq/in....
You would need 352 rollers to equal the support of a basic bunk trailer...
How many rollers you got ??? How much support you got ???
If the issue was that simple, you'd think there'd be an epidemic of sailboat hulls, and especially of powerboat hulls with hefty inboard V8 engines, that would be cracking like eggshells on roller bunk trailers, but they aren't. A boat doesn't need support under every square inch of it's surface. Even a trailer with fixed bunks only has narrow planks supporting it. Most of the boat's underwater surface has nothing but air supporting it when it's on a trailer. The hull's shape and inner reinforcement provides it rigidity. Moreover, about 1/3 of the weight of a typical swing keel boat rests on the trailer frame. The other 2/3 is supported by the rollers. On a fixed keel boat, most of the boat's weight rests on the trailer frame. The rollers only need to carry enough weight to keep the boat balanced upright.
The EZ Loader trailer manufacturing company, as well as other manufacturers, have built many thousands of roller bunk trailers since they were invented in the early 1950s. In this litigious world, if they were damaging peoples' boats, they would have gone out of business long ago.
My present boat weighs 13,000 lbs, and it is stored on the hard every winter, supported only by six jackstands with 12" flat plywood boards on top, and most of that 12 inches square doesn't even touch the hull's curved bottom.
If a boat hull would collapse under it's own weight without external support, it would be a pretty poor excuse for a boat.