Some One Piece characters can get to planetary, so they win because they have multiple.

^Who Exactly Can Get to Planetary?

If One Piece really can be argued to planetary, then it's very possible they could win.

OP characters aren't planetary. You could hypothetically scale off the WB statement, but honestly to me it doesn't make much sense. He's never shown being capable of displaying the power to destroy the planet in one attack anyhow. Overtime yes, but not in one attack

Scaling op to planetary and higher relies on that one statement alone and thus I truly don't believe they are

The writer says that Whitebeard can destroy the world, and he was old, sick with cancer, and unable to use his full strength or Haki at the time.

Prime Whitebeard is 100% at least planetary, then you got dudes who can contend with Whitebeard like Gol D. Roger, Rayleigh, Scopper Gaban, Mihawk, Shanks (maybe) and Kaido (also maybe).

At least 5 planet busters, at most around 7 or 8.

Eh I'm too lazy to debate this out. You can have this one 🤷