From what I understood from the quote currently in her page, the sequence there had only 4 items before the railgun, the chain when fighting Yuiitsu would have a lot more than 4, so we can probably scale them anyway
Nah.
For one, we know Salome started before the fight against Misaka with absorbing weapons.
She did not recognize the barefoot girl.
Her silver hair glittered at certain angles like a CD and it was rolled up on either side of her head like disks or demon horns. She had a small and slender body. Most noticeable of all, she wore translucent raincoats directly over her bare skin, creating a bizarre outfit that only seemed practical if she was worried about getting a victim’s blood on her in a dark bathroom. She held a heavy sports bag by a shoulder strap, but Mikoto seriously doubted it contained baseball bats or lacrosse sticks. Even if it did contain sports equipment, Mikoto doubted it would be used in the intended fashion.
Despite the cold, the girl seemed to be eating a vanilla popsicle.
No. Mikoto had no way of knowing, but that was actually a bleached leather paddle meant for striking people. That tool of torture was easier to use than a whip which required snapping, and it could apply deep and definite damage.
“Lick, lick. Hmm, leather doesn’t taste very good. Or maybe the problem’s the oil rubbed onto it for maintenance.”
Sounding displeased, the double raincoat girl removed the paddle from her mouth. She then easily tore it in two like a rejected contract.
Mikoto did not know the details, but whatever that had been, she knew it was not normal to tear apart that thick a piece of leather with one’s bare hands. It had to be even harder than tearing the phonebook in two.
Contextually, that paddle definitely was a weapon as part of a chain, meaning the list Salome gives later are only the things she absorbed during the fight.
If we count that, plus the bicycle, rubble, telephone pole and iron sand sword she absorbed in the fight, she has indeed 5 weapons, before absorbing the railgun.
But there is absolutely nothing saying that the paddle was the first weapon in that chain.
More likely: That paddle served to keep the chain going that she build up at least from the point where she robbed the bank earlier that day.
Second, Salome gets the power of the weapons she absorbs, so it matters what she absorbs. A 5 weapon chain isn't always the same strength. She could absorb a hundred regular handguns and it wouldn't make her powerful enough to face a railgun.
Her power only managed to escalate so well in the Misaka fight, because Misaka slowly ramped up the strength of her attacks from "weak" to her stronger ones.
At the beginning of her fight against Yuiitsu Salome likely had nothing going.
Then she was lending weapons from her allies, which were indeed implied to be several dozen. However, the things mentioned are a blade, a blunt weapon, a gun, a chain, a flamethrower, a katana, tear gas, a sledgehammer etc. Needless to say, the combined power of such mundane weapons don't come close to what Misaka gave her to absorb.
And from the moment Salome has her chain Yuiitsu stops matching her, being forced into a hopeless battle where she can only survive via her coat blow diversion technique.
Kihara Yuiitsu was using her lab coat to divert the various attacks and keep the damage to a minimum, but that shield of cloth was growing tattered. If the attacks continued, the article of clothing would completely tear apart and no longer function as a shield. Once she could no longer use it, it was all over.
The moment Salome then actually lands some hit, this is the result
Once the initial attack failed, this was back in Mass Murderer Salome’s territory.
She had consumed so many girls to thoroughly polish up her External Offering’s chain. She could now slice a warship in two with a single swing of her arm and she swung that arm almost casually.
Kihara Yuiitsu gave up on using her shield.
For the first time, she jumped to the side with all her might to dodge.
But not even that was enough.
A moment later, Kihara Yuiitsu’s right hand was severed with a noise so pleasant it seemed out of place.
In short, the only part of Yuiitsu that even scales to Salome with a chain at all, is Yuiitsu's coat blow diversion technique. And that only for a chain that doesn't actually scale to the railgun.
Yuiitsu would only scale to chainless Salome, but the best
direct statement we have on her is that she could break a japanese sword with bare hands.
If her chain of destroying weapons and offering them to her god was broken, she would be nothing more than an eccentric with enough ridiculous strength to break a Japanese sword barehanded.