One of the great qualities of an effective leader is the ability to recognize potential when he/she sees one. Pharaoh would have had many reasons not to appoint Joseph as his second In command.
If he was a religious bigot, there would be no Joseph
If he was an ethnic bigot, there would be no Jospeh
If he placed premium on old age as a precipe for effective leadership qualities, there would be no Joseph
If he did not have a dream, there would be no Joseph
If he did not trust Joseph enough by providing him with the enabling environment to carry out his assignment, Egypt would have been doomed.
Pharaoh recognized the spirit of God in Joseph, and he was humble enough to appoint Joseph as his second in command, because he placed the nation of Egypt above every perceived sentiment.
Nigeria should learn from this.