Alot of people said it, including Sanji fans. You just started to see it, because Sanji isn't fighting King so you use it to bash on them.
Yes, the BP are based on strength, but that goes for the ranks itself.
All Star > Flying Six > Headliner > Gifter > Pleasure > Fodder.
But not for inside each of the ranks. There is no ranking in the Flying Six itself, even if some are stronger than other.
Every All Star has the same authority. Same goes for the flying six. There is no indication who is stronger than who.
The only confirmed strength rank we got is King and Queen > Jack. King and Queen were introduced to us as equals.
The card them doesn't always go King > Queen > Jack. Some card games have Queen as the strongest card.
Good that we have to wait for Kings fight to see what he can do, but to say he is stronger than Queen because you assume he will have better feats than him is stupid. Right now his feats are worse than Queens.