Oh, you think Zoro can possibly get 1.720 billion, too?
I also wonder that way about Zoro's bounty, tbh, since CP0 knew that Zoro did not only send King into retirement, but he also took down one third of the Worst Generation in Wano.
Ordinarily, him getting 1.520 billion is the corrent guess, but the WG is so famous and I don't think there is any way for taking 25% of them down not contributing to a higher number.