The grace of the fight was that Tione, unlike Tiona, was going for the kill. Oomori wanted to do both that and for her to not actually kill Argana, so of course he had someone interrumpt it. But well, I guess we won't agree in this, and it isn't even the main point.
Retcons aren't something that actually needs skill. I mean, yeah, a good and seamless one requires it, but not all retcons are executed well. Both the narration and characters directly called Floor 59 the lowest reached by Zeus and Hera. Now it turns out it was actually Floor 71. Finn didn't know how Ottar reached Level 7, but now it is a feat literally all the city saw. DM8 has a scene where Horn and Freya are on the outskirts of Orario while Syr is far into the city.
If Van had an ability to push his status past his actual level Oomori would have said it. Back when Alfia and Zald debuted them being Level 7 was more than enough reason to explain their overwhelming superiority. Yet the next day Oomori went ahead and revealed they had a status above their level because he wanted to. And Oomori made some some tweets after the release of DM17, so it's not that he was against revealing things there.
Also even among the executies the only one who has a level boosting ability is Ottar, and his is an active one with its downsides. Ottar, who is meant to be a cut above the rest even among all the "cuts above the rest" that current first class adventurers are. Van could possibly even be the strongest low-member of Freya Familia, but he is still just that: a low-member. I do not see Oomori giving such a secondary character a skill equal to, much less better, than that of a major character.
I also do not get why people take Oomori's editor for some form of dictator. Of course, they do impose to some degree, but ultimately authors are the ones who decide how to go. Oomori knew GA Bunko would be angry that he revealed Bell's lineage in DanMemo and they did, but he still went ahead with the idea.
In-universe stats from past levels matter, but for practical purposes they don't. Oomori has every now and then thrown terms like "mid Level 4 tier" and "high Level 7 tier". You can't really have "tiers" if stats gap can vary widely, especially at higher levels. In SO6 Argana and Bache are directly said to have higher stats by sheer virtue of having reached Level 6 before Tiona and Tione, which shouldn't be such a deciding factor if stats from five past levels mattered.
Gareth can move roughly as fast as Finn despite a gap of around 300 points per level. Despite a gap of around 400 points across four levels, one of nearly 700 at Level 5, and one of over 900 points at Level 6, Ryuu had a Strength stat that could compete with Hogni's even before casting Agaris Alvesynth. Sure, she had her skill Mind Load and sword Alf's Justitia, but we are talking of a gap of over 3000 points.
How many points does the rank up bonus grants if it can render such a gap meaningless? What even is the point of grinding stats for years if a regular boost (Mind Load) and a weapon appropiate for one's level (Alf's Justitia) grant a much more greater advantage than even maxing out one's stats?
Even if they did matter Bell's status didn't make sense. The system is supposed to work in a way that an adventurer with S999 in Levels 1, 2 and 3 would still be no match for a Level 4. But yet there is supposed to be a way in said system for a Bell with only 200s-300s total "extra points" per stat to have Level 4 prowess while only having D rank stats as Level 3. Making them not matter is honestly as ilogical as it was to make them matter as much as they did.
Actually Dormul is indeed supposed to be a cut above the rest in regards to Level 3s:
Bell and Dormul were both second-tier adventurers. However, Bell had only just recently leveled up, whereas Dormul had reached Level 3 nearly three years ago. In terms of strength and skill, the dwarf was a true veteran. Therefore, he possessed a distinct advantage.
And I didn't assume Bell was his equal in skill because he fought him as an equal. As I said, I do think Bell had prowess above his level in previous volumes, and of course that could make up for a skill gap. No, I said he was his equal because the narration says so.
Eina’s surprise came from the fact that Bell truly looked like a second-tier adventurer.
Even compared to the experienced Dormul, the crispness of his actions was in no way inferior. He wasn’t relying on his Status’s blunt power; instead, his form was conjuring images of a former teacher from the top-class adventurers.
Also, there is how in DM18 Bell refers to him easily defeating Van as the result of the gap between a Level 4 and a Level 5. For as many faults as Oomori has, assessments of Bell's prowess ain't a mistake. Be it narration or characters, they have always been right. Even though when he is above his level Oomori never said so outright, he did state his stats were equal/close to those of someone from a higher level.
Yet in that scene he left it simply as that his power was just that of a Level 5. Not even something like the "mid Level 4" status and "high Level 4 agility" he put back when Bell had become Level 4, but plain and simple Level 5.