Possible Clues:

• How kind of them to need fifty more to be of high rank
• Biology classes?
• Classes are bowled over by information
• Varieties
• Being so kind, they need another fifty to be in command
• They're kind of needing another fifty for the commander
• Finish off officer classes
• They're kind enough to give a start to 8 down
• Officer detailed similar groups
• Classes an officer does not complete