That is true..
Oden was never shown to be equal to Whitebeard or Roger.
Even Kaido surpassed him, got stronger.
In this scenario we have Harald literally knocking out the strongest pirate aside Roger and Whitebeard.
That is crazy...
It make however somehow sense.
oda always hyped Elbaf, always hyped how strong the country was....
Make sense that the strongest Giant in history is beyond Oden lvl.