I tell you, man, don't just based on the statistics, based on the quality of opponents these two boxers have fought.
Check the record of Donaire https://boxrec.com/en/proboxer/48243
here are some of the names of the champions that he beaten.
Nordine Oubaali
Vic Darchinyan
Jorge Arce
Fernando Montiel
Tell me, what are the big names Gaballo beat in his boxing career?
On the other side we can't set aside to look for the fact that these statistics of a fighters will be used as a basis to determine the odds that may favor towards a fighter. But you still have a point mate, those statistics are just the statistics of a boxers past and recent fights and for sure every fighters have had an improvement in their physique's, in their strategy and improvements in their speeds and skills but there are given skills that are the true assets of a fighter that can be seen through out his fights. Donaire is such a good boxer and Gaballo is also a good one, so I can say that the upcoming fight is a very anticipated fight.
This is the basis of the expert to see who's more stronger among those fighters but when the fight is on things will be different since we might gonna see that the other fighter will change it phase and been more prepared for this fight, also age might be consider unto this since we know Donaire is not the same as before but let see what performance he can show and I want him to win against Gaballo so that we can see a possible rematch between him and Inoue.