Rokushiki is based on physical strength is actually based on a

Why does Lucci (One Piece) have a power level of 4000? This is the same power level as Nappa (Dragon Ball). Lucci is mountain level - island level at best. - Quora

What power is it? : r/OnePiece

Who's-Who still hasn't revealed his true strength! - One Piece

Rokushiki is based on physical strength is actually based on a mistranslation in earlier One Piece volumes : r/OnePiece

One Piece 1068 brings back Lucci's Rokuogan

In One Piece, why do the members of CP9 learn to use the “six powers”, but not haki? - Quora

Character Profile - Rob Lucci

Chapter Discussion - Rokushiki is based on Haki, Page 5

Remember when Oda tried to introduce a Power Level system? I sure didn't. Glad it never came back, tbh. : r/OnePiece

Chapter Discussion - Rokushiki is based on Haki, Page 6

Illustration - Rokushiki Robin artwork

Rokushiki is based on physical strength is actually based on a mistranslation in earlier One Piece volumes : r/OnePiece

Skills/Devil Fruits/Rokushiki, One Piece Endless Treasure RBX Wiki

Chapter Discussion - Rokushiki is based on Haki, Page 7

Honestly Oda probably should have just expanded on Rokushiki instead of creating Haki. He could have definitely made it to where there are techniques that allow you to hit logias and armament