That his 3.6b bounty isn't just because of his strength, no one has a bounty just because of their strenght excapt MARINES by buggy bounty system.
They never said all 3 are not boosted due to Marine Hunting.
You don't mention that on purpose now.
You dodged the question if you believe Crocodile > Zolo based on bounty or not.
Also Buggy not having a bigger bounty than 3.1 billion doesn't help you as well. That means making Mihawk + Crocodile your underling + hunting Marines with Cross Guild only gives him 3.1 billion, if you think Mihawk is a top tier, then it should've been higher than 3.1 billion considering Buggy controls a top tier power + hunting Marines and being a major threat to the Marines, different than what other Yonko does.