Remember the aggressiveness of your approach is a combination of pad, product, machine, and technique (pressure, etc.).
Your polish (product) is fairly fine, but you have heavy cutting pads in the orange Hybrid and cyan HydroTech, so you already have the most aggressive (foam) pads in those two lines.
Your Flex is capable of doing more work than your PC. Your choice here comes down partially to how many steps you want to do, what level of defect removal you want, etc.
Since it's a white car, if you're not looking for perfection, and prefacing this again with my not having any experience with the Hybrid pad line, I'd do a test spot with the Flex and your blue pad. If that gives you satisfactory defect removal and finish, then you're done. If it doesn't have enough gloss, follow with your PC and the tangerine pad.
If it doesn't give you the defect removal you're looking for, go to Flex/orange Hybrid, if it's good you're done, if the gloss isn't there follow with the PC/tangerine, if the defects aren't gone you will need to retreat and get a more aggressive polish like Optimum Intensive or Hyper Compound, or a more aggressive pad (doubtful you will need that).
When you say 6 passes--um...we're not talking about 6 "sets" where you apply polish 6 times? You probably want to cross-hatch your section, and if you do it three times each direction...that's 6 passes?
Remember small sections, slow arm speed.