There's no way you actually believe zoro and fs luffy or katakuri and king have similar reaction time
I said your claims are groundless, not that I believe the opposite. I don't see why these characters can't have better or similar reactions than them. It's not impossible like you pretend it is.
Zoro, as a matter of fact, reacted to Hakai faster than all Rooftopnova and was also able to detect Apoo's attack coming at about the same time as Luffy.
It means kizaru is extremely fast likely being the fastest character in verse. With enough speed you can tag anyone even someone with fs. Characters without fs are still going to struggle significantly more
So you agree with people can be as good as FS users or even outdo them without having FS, which is the whole point of my argument. Kizaru does it via physical speed while others might do it in their own way. No one said FS doesn't make a difference, but it doesn't always make a difference.
And just because kizaru can fight and tag characters doesn't mean marco can
He should be able to because Marco kept up with him in a fight. So if he can operate at that kind of speed, then he operates at the levels of speed required to pressure FS users.