I think that we are indeed short of quality in the GK department, but not necessarily because of the understudies.
I have never rated Max O'Leary. But the argument always used to be that he never had a run in the team. Well, now he has. And I still don't rate him. I don't think that he is awful, but I still believe that he is a League One keeper at best.
Both of the understudies are unknown to most. But at least there are two of them.