Also to disprove your point.
When Brannew is talking about Mihawk's bounty he doesn't mention Mihawk's bounty being inflated by the Cross Guild stuff.
Here 2 Cross Guild scenarios..
Example 1
Mihawk get his WSS Bounty - 3.590 Billion
Buggy and Crocodile get increase for their part for their threat level part from Mihawk..
Buggy - 3.189 Billion
Crocodile - 1.965 Billion
Example 2
Buggy gets his Bounty first- 3.189 Billion
Mihawk and Crocodile get their Bounty upgraded for the Creation of Cross Guild with the 3 of them..
Mihawk - from 2.590 Billion to 3.590 Billion
Crocodile - from 965 Million to - 1.965 Billion
The 2nd seems more likely to me..