I played beta for 3 months (how I wish I had just bought the japanese version), and yes the Thief/Ranger combo is a good combination, but one of the better combinations will be when you can have 2 advanced jobs i.e. the Ninja/Ranger combo or Ranger/Ninja because with Ninja you get the dual wield ability. personally I'm going Nin/Rng. but as of now I'm Whm/thf for the easy partying for being whm, and gathering gil with thf ability.