The Superhero Database Classification number, or SHDB Class, is a number that represents the overall 'power' of a character. All traits of a character are used for calculating the Classification.
What it DOESN'T mean
This doesn't mean that a higher class would always beat a lower class character. But the bigger the difference in Class is, the more obvious it is who'll win in a fight.
How is this calculated
( INT^1.3 + (STR*0.5 )^2 + (SPE*0.5)^2 + DUR^1.6 + (POW + (SPS*SPL))^2 + COM^1.8 ) ^ TIER
Super Power Score and Level
Every Super Power has a score (SPS) that is used to calculate the Class. Each Super Power also has 3 levels (SPL). The level is set when connecting that Super Power to a character. The level determines the final score, of the Super Power, being used in the calculation.
Naruto, on the other hand, has at least moon level stats (e.g. feats vs Toneri & as SO6P Chibaku Tensei), so claiming Yhwach's future manipulation could prevent / change Naruto's level of power, too, is a NLF.
Yhwach's "Almighty" (future precognition) was proven it could not really keep up with when 4 people fought him simultaneously (Ichigo, Aizen, Renji + Uryu), so Uryu's silver arrow hit Yhwach because he didn't see it coming.
That's why I believe Naruto should be able to overload Yhwach's "Almighty" by splitting into 1000 shadow clones, too.
^ completely negs all of prime ichigos abilities and blitzes him as if he's slow as hell, he could do the same exact thing to naruto, if naruto attempts to blitz him yhwach can use the future and blitz naruto instead, and he can neg all of narutos abilities