My reasoning might be speculative but it might help anyone who is looking to bet on this game. Some of you might question why Naoya Inoue challenged Stephen Fulton. The reason is simple, he is exceptionally talented, and with his accuracy to punch hard, he is worthy to challenge Stephen Fulton. Stephen Fulton has an impressive boxing record, he has shown the world his impressive defensive skills, and impressive footwork but lacks attacking abilities as per my understanding. Overall this would be an interesting match to watch and my research says that Naoya Inoue is a little better than Stephen Fulton. If betting is my primary objective, then I would bet on Naoya Inoue.
Both fighters wanted legacy fights hence they want to face each other. Fulton has the chance to become a 2 division champion by rematching Figueroa at 126 but he opted to face Inoue the current pound-for-pound # 1 or #2. This fight is also more beneficial financially for Fulton and instead of moving up, there is a chance for him to become undisputed.
Inoue on the other hand is not just chasing for legacy but historic records as well. Inoue used to be the quickest Japanese to become a world champion only in his 6th pro fight. He became a 2 division champion in his 8th professional fight and I believe this is a world record. If Crawford cannot win against Spence next month then Inoue will also have the chance to become the first 2-division undisputed champion in the 4 belt era.