That is what the Germans did during WWII and it seemed to work well for them. What really made the German system work well however, maybe wasn't so much where the officer candidates came from. What probably made it work well was they absolutely refused to lower their officer recruitment standards, no matter how short of junior officers the Army was. They rigidly maintained their standards right up to the end I believe.

It may be key that personnel depts. entreaties to fill slots with bodies be resisted at all costs. They weren't in Vietnam to our sorrow. So have the moral courage to keep your standards up and the exact system may not be that important.

This is the opinion of an always been a civilian who has an interest in these things