That doesn't even make any sense
Luffy's bounty is lowballed, we know the WG are concealing information about Luffy and downplaying his achievements.
His bounty is QUITE LITERALLY not low balled, it might even be a bit inflated because of Nika sperm
Blackbeard did the following
-Double Crossed World Government
-Got the most credit for killing Whitebeard
-Destroyed Marine Ford Plaza and caused Chaos
-Was yonko for whole two years
-Had Impel Down Jailor who is basically biggest Navy device after admirals under him
And he got only 2.2 Billion
It took another Admiral, and a Fleet Admiral candidate to work under him to get 3.9 Billion
Going by Blackbeard's 2.2 Billion, Luffy's bounty is more than justified if not overinflated
Law and Midd inidividually deserve 1 Billion at most but Luffy propaganda got them 3 Billion.