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.
This is not even close to saying that Raditz would lose, in the first dragon ball at the end, they already far exceeded the island level range by quite a bit, and Raditz is capable of devastating more than that, the calculations are not even valid for a versus, the Forums to give arguments are very bad information, Raditz by difference was already much faster than an attack that could itself destroy and go to the moon with relative ease, how do you see this even?
Raditz by difference was even able to Humiliate both Goku and Piccolo, since he easily dodged Piccolo's attack as if nothing had happened and resisting an attack from Piccolo as if nothing, else is better in melee aspects