It aint the same since:
- Doflamingo's bounty was frozen while Kaido and Big Mom wasnt.
- Kaido's and Big Mom bounty wasnt splitted otherwise Killer and Zoro would also get credit of it.
- The winners don't always get the full bounty of the lovers just as Zoro and Sanji with Queen and King.
500 million berries for Luffy and Law was too low for their level. They already were Yc1 fighters as seen with Luffy soloing Katakuri and Law being able to fight an Emperor as Big Mom 2 Islands later with no PU's.
Heck, we have Zoro with no real PU's being able to fight Emperors too, and defeating King and getting a bounty more than a billion just as Jimbei.
So Law and Luffy already were worth a billion since dresrossa, or even more.