What was Majin Yamu & Spopovich's power level in your opinion?

[Beek King]

Isn't the whole thing with Goku at the very start of DB having a power level of 10 just something that came from a fan power level chart?

It's official.

Spoiler:

Hmm, thanks for reminding me, though I still find even official sources sketchy at times. If a normal man is level 5 while a bulletproof untrained Goku is 10, where do stronger fighters that are still hurt by bullets such as Videl fall then? Or someone like Ox-King who can crush tanks with his fists and have cannon rounds bounce off him, but can't master a Kamehameha? (speaking of him, IIRC one source stated his PL is 900 which is definitely exaggerated, I doubt he trained at all between DB and DBZ and if that was his power all along he would have crushed all DB-era villains then).
Overall, trying to apply power levels to OG Dragon Ball and non-superpowered minor fighters in DBZ is a headache.

[Nejishiki]

If a normal man is level 5 while a bulletproof untrained Goku is 10, where do stronger fighters that are still hurt by bullets such as Videl fall then?

He already has twice the power of an ordinary person. What’s more, his body is tough enough to repel a gun’s bullet.

Goku's resistance to firearms, which isn't perfect, is credited towards his Saiyan body. The translation linked does categorize these factors separately. Learning the Kamehameha wouldn't be related to one's Battle Power though. I can't say any official source claims Gyumao's Battle Power as 900 either (it's likely misinformation unless you can point me towards the right direction). With that said, early Dragon Ball utilized the concept of ki differently before God trained everyone. I think it makes sense considering Earthlings favored concentrated techniques & physical ironing beforehand.

[dragonball0900]

If a normal man is level 5 while a bulletproof untrained Goku is 10, where do stronger fighters that are still hurt by bullets such as Videl fall then?

He already has twice the power of an ordinary person. What’s more, his body is tough enough to repel a gun’s bullet.

Goku's resistance to firearms, which isn't perfect, is credited towards his Saiyan body. The translation linked does categorize these factors separately. Learning the Kamehameha wouldn't be related to one's Battle Power though. I can't say any official source claims Gyumao's Battle Power as 900 either (it's likely misinformation unless you can point me towards the right direction). With that said, early Dragon Ball utilized the concept of ki differently before God trained everyone. I think it makes sense considering Earthlings favored concentrated techniques & physical ironing beforehand.

To be perfectly honest, Akira Toriyama didn't have the concept of saiyans back then. There's also Krillin who, while being hurt, can still resist bullets, and not get instantly killed.

[Beek King]

If a normal man is level 5 while a bulletproof untrained Goku is 10, where do stronger fighters that are still hurt by bullets such as Videl fall then?

He already has twice the power of an ordinary person. What’s more, his body is tough enough to repel a gun’s bullet.

Goku's resistance to firearms, which isn't perfect, is credited towards his Saiyan body. The translation linked does categorize these factors separately. Learning the Kamehameha wouldn't be related to one's Battle Power though. I can't say any official source claims Gyumao's Battle Power as 900 either (it's likely misinformation unless you can point me towards the right direction). With that said, early Dragon Ball utilized the concept of ki differently before God trained everyone. I think it makes sense considering Earthlings favored concentrated techniques & physical ironing beforehand.

To be perfectly honest, Akira Toriyama didn't have the concept of saiyans back then. There's also Krillin who, while being hurt, can still resist bullets, and not get instantly killed.

Yeah, I was also gonna mention that but people usually bring up the fact that those scenes with Launch spraying them with bullets were more gag oriented in nature.

[Nejishiki]

Kuririn isn't comparable to a normal human. I'm not gathering the motive for dismissing supportive replies with that reasoning. There's an entire Dragon World to consider. Concerning Kuririn & Turtle Hermit, while they know how to counter & resist firearms, it does harm them more than Goku. The solution to the puzzle doesn't require strictness.

[Hugo Boss]

Who's the strongest character you think they could win against after the power up they've gotten from Babidi?

Probably anyone who is within natural human limits by Dragon Ball standards. For example, Goku and Kuririn at the start of their training under Master Roshi.