Most Christians already own most (if not all) of these books, and if they would simply take the time to read them and put the various principles into practice, there would be no lack of true Christian "leadership" in the world today.
Sadly, most Christians do not read these 5 books in search of leadership advice, nor do they put into practice Jesus' commands to wash feet, love enemies, serve others, and place the needs of others above their own.
Instead, most Christians are obsessed with a more worldly style of leadership that involves hierarchical authority and exerts power over other people rather than exerting the "power under" form of loving service exemplified by Jesus and His Apostles.
In these 5 books, Jesus spends all of his time talking about "followership" or "discipleship". In fact, all of his best teaching on "leadership" actually has to do with "followership" since in the Kingdom of God the greatest among us is the servant of all.
If you start to notice someone talking too much about leadership and not actually doing any actual serving of others, then you're probably not dealing with a Christian leader.
Real Christian leaders do not spend all their time talking about leadership. Instead, they quietly continue to follow Jesus, serve others, and love the people right in front of them.
Someone wisely noted that "Leadership is all about making more leaders, not creating more followers" and that is the problem with "Leadership" as we know it. The emphasis is always on being the leader - or "the one in charge". Is that what we see in the Gospels? No, it's not. What we see is Jesus' emphasis on following Him, and on teaching others to follow Him, too.
The Great Commission is not for us to "Go into all the world and make leaders". Our calling is to go into all the world and make more disciples (followers of Jesus), who in turn teach others how to follow - not to become leaders.