Given that there are only 4 at any given time the world government or marines decide this. Otherwise Luffy would have been named the 5th emperor by Morgans and that would have been that.
Well with Kaido it's objectively true. The straw hats pretty much took out all of Kaido's strongest subordinates themselves.
It's really hard to judge pre-time skip yonko strength with post time skip strength, but outside of Marco, Whitebeard and Jozu which of Whitebeard crew at marineford...
Vice admirals are weak as shit at this point.
Every time they've gone up against someone that's supposed to be really strong they've gotten their ass handed to them. A half dead Whitebeard almost killed Akainu, Luffy dominated Kizaru, I doubt any of them could beat Blackbeard or Shanks one on...
You clearly weren't following one piece fandom at the time. Who was going to join the crew was a huge debate. He definitely wasn't unexpected.
I was always team Paulie myself.
It's one of the worst arcs in all of one piece and easily the worst post time skip arc.
It's the best arc to remake because they can fix how terrible the pacing is. They still can't make Hody a compelling villain, or bring any level of stakes to the arc.
The poison was obviously a ruse. Everything we know about Shanks points to him never using such tactics.
Barto fucked up and he had to a pay a price for it, the price he paid was far better than the one Kid got. They'll show up later in the Mr. Nika-go or something.
Shanks absolutely knows...
Their immortality and overwhelming haki make them stronger than their physical ability. Not that they aren't insanely strong. Luffy would have beaten all five of them if they didn't regenerate. Hell even Zoro clashes with one of them.