Yep, or another example: going up the front side of Hamilton.Agreed.
For a road like Morgan Territory, few vehicles could ever keep up with a sumo, IMHO. But on more open roads, a car will have an advantage in the corners due to not having to worry as much about debris and having twice the contact patches, both in size and number.
I had a Toyota catch up to me in Berryessa when there was a construction stop when I was on my '13 ZX14r. I could lose him easily in the straights but that car dove into corners (using both lanes at times) a lot deeper than I was comfortable given the road conditions. (debris, tar snakes, etc) I felt it prudent to just pull over and let him pass since I had nothing to prove and more to lose.
If you're staying in your lane, there's a lot of really narrow stuff that severely limits the lines a car can take. A supermoto has significantly better power to weight, enough suspension travel to soak up the road, and is much narrower so there are more line choices.