Heroism of a King Captured on Film in the Movie of George VI - January 8, 2011 - The New York Sun
History is lived going forward. The participants do not know the outcome and just hope to muddle through day by day. Given that when the lives of others are at stake all that can be relied on is education and temperament. The education of the Royals a hundred years ago was shockingly poor. It consisted of Church and some Court ritual, with heavy reliance on experts to know what things actually meant, and some naval experience. There is no clear answer on what would work better but given the example of Edward behind them efforts have been made to do better with Charles and William, with varying results.
Edward's temperament was poor, even if as Lord Black holds it was better than feared. Certainly his weaknesses combined with his prejudices would have made him a disaster if he had held on. We can only speculate what such an alternate history might have produced. It was a very near thing.