1) Short course times aren't very indicative, mainly because the top guys don't compete or aren't in top shape.
Wellbrock swam 14:06 when he was 14:36 long course. Hafanoui swam 14:10, which translates to 14:40 at best -> 9 seconds slower than he went this week.
When Wellbrock was as old as Hafanoui was last year, he went 14:36. Now, 5 years later, he improved by 2 seconds. Hafanoui on the other hand improved his PB by 45 seconds this year. Wellbrock improved his PB by 19 seconds when he was younger than Hafnaoui, while Hafnoui improved his PB by 45 seconds while being older. Saying that their progression is remotely comparable is completely absurd.
2) Really wonder how often he got tested after being completely irrelevant last year. Would love to see the number of his tests vs. the number of Wellbrock's tests. Also would like to know who is responsible for him. Hard to imagine tunisian officials regularly flying around the world just to test him. Maybe he wasn't faster because he wasn't rested or maybe he wasn't faster because he couldn't go faster. Anyways you have to admire his "confidence", he doesn't ever need to go fast before worlds/olympics to test his training, somehow he just knows that it will work out and that he will always drop massive amounts of time. You almost have to envy him ...
3) How about you stop throwing around the word "unrested"? If Short would have gone 3:42 unrested, he would have gone at least 3:38 at worlds. If you go 3:42 unrested you don't drop less than two seconds when fully rested. His 3:42 in-season is still infinitely more impressive than anything Hafnaoui ever did in-season. I still haven't heard why exactly Märtens and Wellbrock, who were both already qualified after last year's worlds, had to go fast in-season, but Hafanoui and Short (who both weren't qualified) didn't. The mental gymnastics you need to justify this point of view is astonishing.
Edit: I just calculated by how much Hafanoui improved his PB in the 400/800/1500 free vs. by how much everyone else combined (all finalists in the 400/800/1500 free) improved their PB:
Overall improvement by Hafanoui: 39.90 seconds (3 races)
Overall improvement by everyone else: 41.04 seconds (21 races)