Judges 7:4 And the LORD said unto Gideon, The people are yet too many; bring them down unto the water, and I will try them for thee there: and it shall be, that of whom I say unto thee, This shall go with thee, the same shall go with thee; and of whomsoever I say unto thee, This shall not go with thee, the same shall not go.
There must be barriers to leadership training. First the cowards went home and then the careless. Those who can be trained for leadership will be comparatively few. Maybe all could go on but not all will. Some will be afraid. Others will want to do battle their way. Others will be careless but some will keep coming back for more. These you can train.