True, no such thing as an easy fight in boxing especially if you are fighting unpopular boxing because you are not so familiar with his style but the thing with Donaire, he has this experience advantage over Santiago which I think should offset with the Filipino Flash's age disadvantage so this makes the whole fight even.
Donaire is very serious now with his training as he knows that fights on this stage of his career is tough and he is very discipline so this gives him a slight advantage over Santiago.
who are on such condition on which it is really that normal that they would really be trying out to suppress out that kind of risk via doing hard training which would be able to patch up
with that inevitable disadvantage but overall we do know that he does have that speed and good countering which it isnt really still rusted despite of having the age.
I could see that he could still pull off this fight.