To really know, we have to start counting his backhand loops and compare with other top players. I started to do it for the match against Anders Lind, but when I counted to 10 successful loops and 3 failed I gave up in the middle of the second set, because it seems pointless. Because what is considered a loop? Truls uses his backhand in such a diverse way that it is hard to categorize it. From what I see though, and the feeling I have about his game, is that there are probably 20-30 players in the world that could beat Truls in a crosscort backhand to backhand loop duel. I also see that Truls backhand slow loop is very successful and scores a lot of direct winners. And his backhand punches are amazing.
I really like your post. Your 20-30 is way too high. I will make another along the same lines. I have a coach friend who makes fun of Truls backhand technique. I used to laugh with him too until about a year ago. I concluded that Truls had improved his backhand opener and rally topspin so much that Harimoto was blocking Truls' opening loops off the table. And to me, you can make fun of someone's technique but when people are struggling to block his opening loops and he is making them at a high clip, his technique is at least adequate, and you really have to stop debating technical aesthetics and accept performance and functionality as long as there is no serious tradeoff. Truls beat Harimoto on the backhand diagonal in a close match a year ago (I think it was after the Olympics but it might have been in the year before). I say that because Harimoto kept attacking the backhand and lost critical points doing so. Obviously the Olympics were the Olympics but there has been a lot of work by Truls since and anyone looking at his play with fresh eyes will notice it.
Along the same lines, in 2016 before the Olympics, Quadri lost 0-4 to CCY. IT was a really ugly match where Quadri looked clueless against tactics to exploit his backhand. He then trained his backhand block and exchange to a point where it took stronger performance to break it down. Quadri reversed that result at the Olympics, not by developing a great backhand topspin, but by being much more consistent doing what he did at the time, which was block and hit on the backhand and by playing better forehand as well. Till today, and sometimes I am a victim of this but not as naively, people say Quadri has a bad backhand because they keep focusing on backhand topspin rather than overall backhand play.