Never took Capricorn for Mages. I think we do better when were something that doesn't use "magic". I think Samurai or Dragoon for us would more fitting. Notice how they gave all the Cardinal signs the Mage jobs but gave the Fixed and Mutables the damage tanking jobs? But here'd be my interpretation of the zodiac job system for everyone.

Aries: White Mage (Still)
Taurus: Dark Knight
Gemini: Machinist
Cancer: Red Mage (Still)
Leo: Knight (Still)
Virgo: Chemist
Libra: Freelancer
Scorpio: Time Mage
Sagittarius: Ranger/Archer
Capricorn: Dragoon
Aquarius: Samurai
Pisces: Black Mage

Agreeable list or do you have your own list? I'd be too dumb to use magic. Personally I don't see myself as a glass jaw.