It's not an issue if it worked - if he produced people who were able to replicate his skills consistently and pass those skills along to their students.
If that's not the case (and, IMO, it isn't) then all this talk about how these are valid teaching methods is meaningless.
Yes, that is what I am saying. Those students became proficient in their skills, even if the Founder held back information. As easy as it is to look just at his post-war students, his pre-war students also where very skilled. The basal separation of each group is in the Founder's change of philosophy that has nothing to do with him holding or not holding back information. Whether post or pre war students those who are well known and responsible for spreading Aikido where the top of the class. No one in their right mind wouldn't put their best students forward.
Aikido would have never grown if the Founder didn't understand the value in sharing information. You can't have epic failure in representation when getting people's attention. For years there has been a low hum of dissatisfaction with the Japanese students first taught by the Founder. The complaint is they didn't tell non-Japanese students everything. An argument that may have validity. If you really want to sabotage the empire that was built, withhold information from everyone. Fast and easy way is to seal the lips and don't demonstrate. Instead lie and fake it. But the problem with that is, students will catch on very quickly and afford no validity to the teacher and move on.
Not everyone is a grand old teacher either. Many people have great adeptness, but are unable to communicate as well as other which they are measured. That isn't fair. In the face of that, the students of the Founder where successful enough to expand the interest of Aikido. It is meaningless.