I guess One Piece was really filler till now
Luffy - works his bounty to 3 billion, defeats several warlords with Crocodile being first one, who was also crushed by WB, Impel down, Marineford, defeats two Commanders of a Yonko, Grand Fleet, defeats Kaido - 3 billion, cool
Crocodile - crushed by WB, defeated by Luffy, off screen and now he would have had a bounty higher than Luffy's if the Navy didn't mistake Buggy as the leader
Logic 1+1=3