I guess it depends how much of a factor you think the difference in poundage makes between a prime Chang at jnr fly and Arbachakov at fly. Chang was pretty much untouchable at jnr fly ans only fought once at fly when he was past it. Their common opponent there was Muangchai Kittikasem, who beat Chang and then lost twice to Arbachakov. I’d probably lean towards Yuri in this one.
To school someone like Chang,you need to be defense-first, Yuri wasn't really one so yeah, Chang can do this,and if we're talking about prime Chang just going up in weight,I doubt he'll be in much trouble.
Arbachakov just based on the mere fact that Chang was unsuccessful at Flyweight. Even if were to place a prime Chang at Flyweight I think he'd be in deep against a fighter who was technically efficient and a vicious puncher. An entertaining match up for sure but a fight that I can likely see Arbachakov giving Chang lots of trouble with his sharp shooting and counter punches. Chang's only chance is if he manages to outwork Arbachakov, smothers his offense and spoiling without getting himself hit with any serious blows, which would be a tough task for him.
