I know this might open a can of worms, but I don’t think a LV 20 human could defeat Goku. And Borusel is on a similar level of power.
All the way back in OG Dragonball, Kid Goku gets shot in the head by a handgun and survives. Not to mention Launch’s much deadlier machine gun.
And while Goku did get a slight bruise in Super from a bullet, he caught 99% of those, and the only reason he got bruised was because he hadn’t been training, and he wasn’t even powered up! And Borusel’s base form is Super Saiyan God levels.
Plus, I’m pretty sure that the LV increase strength/attack power, not speed, as the soul moves at the same pace. At the beginning of the Saiyan Saga, aka the beginning of DBZ, they start not being able to see the battles with their eyes. And even if speed increases, Super Saiyan from just the beginning of the Android/Cell Saga (so Future Trunks) takes out Cyborg Frieza in 5-10 seconds if you watch the real time clip from DBS: Super Hero. And they are far beyond that level now. Also, in the same saga, Goku blocks Trunks’ sword with just 1 finger, which cut through Frieza like butter.
