Why do you guys want A PARALLEL ???
We don't need another Whitebeard, We don't need another Shiki, we have Kidd, Buggy, Katakuri, Blackbeard, Law. That's the new guys.
Maybe they will be not as strong as Whitebeard in the future but that still make sense.
Whitebeard / Roger / ( Big Mom )
Next Generation
Kaidou / ( Big Mom ) / ( Shanks ) / Mihawk.
New Generation
Luffy / Blackbeard / Mihawk