Tier 1:
- Admiral
- Smuggler
- Navigator
- Helmsman
Tier 2:
- Diplomat
- Engineer
- General
- Tinkerer
- Saboteur
- Tycoon
Tier 3:
- Revered Elder
- Foreman
- Pirate
- Lieutenant
- Princess
- Infiltrator
- Sentry
- Intelligence Officer
- Assassin
- Security Chief
- Double Agent
- Thief
- Martyr
- Hypnotist
- King
Tier 4:
- War Hero
- Minister of Energy
- Inspector
Note: For specialists that require promotion, I'm ranking them based on their value relative to their cost. Same for Assassins and Saboteurs, which provide multiple specialists at a time. And of course this is no replacement for an in-context decision based on the particulars of the actual game!