Promotions and medals give an armed service ways to reward people it wants to retain. Promotion can be easier to justify outside the service. A high decoration can require more public explanation, particularly if it involves presentation by a monarch or other head of state. That scrutiny can make a promotion more convenient when the service does not want to explain the circumstances widely.
Chapter · 50:27-51:15
Why promotion can be easier to explain than a high decoration
The public explanation required for a high medal can make promotion the more convenient reward.