Even if Servants were to get downgraded to Low 7-B, I feel like random masters who in general don't act aware of real world weapons (Assuming they're typical like the Tohsakas), and probably wouldn't consider nukes in every statement.
It's not like nukes are plausible for them to get, reasonable to use, or even effective since their magecraft works just as well if not better, so it makes sense they wouldn't consider them.
Well in fate redline servant battle in the middle of a nuke, and not all servant are 6-C in dura, many are 9-B but they still can't be harm.
Knight of owner talk about servant would just outright ignore bullet of fighter jet.
He can take control of the missiles it launches so that they track down opponents, and while the bullets of a fighter jet would generally be easily avoided or outright ignored by a Servant, they become fast and powerful enough to be a serious threat under the effects of Knight of Owner.
Here too Nasu mention it
Fate/stay night Premium FanBook, p.047 - Q: How strong are Servants?
But what makes these guys dangerous is that since they're spiritual bodies, regular weapons won't work against them. As far as destructive power goes, there are more numerous powerful weapons among modern ones, but as normal weapons won't do a thing to them, they're among the most powerful.
And we have this in fate heaven feel day 15.
"Right, next question. Are Servants still spirits even if they take physical form? So you can't hurt them with normal weapons?"
"…Let's see. A normal Servant will be able to nullify them, but those consumed by Sakura are another matter.
Having received bodies from Sakura, they cannot return to spiritual form.
Strong magical weapons should be able to penetrate through their shadows."
"I see, then it's decided. There's a chance of victory, and the roles are clear.
Rider. I want you to beat Saber one-on-one. To be specific"
Same for the scan you used it's can't be used to talk about the intangibility as it was used to describe Arturia and Arturia in fate stay night can't become intangible.
"Me? …Well, okay. So in short, you are misinterpreting that Saber can be only hurt using sorcery, right?"
Uh-huh. "in short," right. That'll be the day.
"Uh, no… that's not exactly what I meant.
I just thought it was amazing if the armor is that strong."
"Of course it's amazing. Not just Saber, but all the Servants are heroic spirits. There's the fact that they're spirits, but they can't be hurt by normal means. That's because Servants themselves are divine mysteries."
."The only ones that can physically hurt the Servants are other Servants, heroic spirits like them. So in other words, if a Servant was using it, even a paper knife could hurt Saber."
Here another mention and adding prana to thing is what alow normal thing to affect servant but it doesn't make these attack automatically 6-C so it's not about strengh of the thing (otherwise knight of owner of lancelot would not need to exist as it's the thing that make modern weapon equal in strengh to servant). It's just that servant are Mystery and only Mystery can affect mystery.
Rocks tore through their skin and even damaged part of Ruler's armor. An attack without prana
accompanying it could never harm a Servant. But prana had been loaded to the point of bursting
into the sword he swung, and it had even contaminated the broken pieces of stone.
It was the same as a Servant throwing dirks with prana loaded into them… Though, it was the
first time Ruler had witness of the phenomenon of prana clinging even to fragments smashed
apart with a sword.
We have that too, servant weapon can hurt servant because they are spirit form like them.
"There are ways for even us to defeat Saber.
We just need to use magic that exceeds Saber's magic resistance, or use the weapon she uses and cut her neck while she's asleep. Servants' weapons are in spirit form like them, so they should be able to hurt them."
