:welcome:to AGO! :cheers:
Great choice with the Flex, it'll serve you well for sure. :xyxthumbs:
I would agree with the post however that you invest in SEVERAL more pads. If you're only going to be doing your 3 vehicles (and considering they have completely different paint systems RE soft/hard etc.) you'll still need at least a dozen pads. Easier to have 18~24 than trying to work with only 6.
Normally I'd say 4 of the orange, white and blue, then something like 2 yellow, black and red. But that only applies to Lake Country pads other than the Hybrid models. Why? Because for some strange reason the 'normal' color/cut combo with all the other pads is different with the Hybrids.
For instance, yellow is always known as the heaviest cut foam pad you can get. That is with everything EXCEPT the Hybrid pads, where there yellow is a light polishing pad. More similar to what the blue is in the regular pads. Where the blue/cyan in hybrid is a cutting pad with more cut than the white pads. (Has less in all other forms of LC pads.) But hey... at least the white pads are still right there in the middle.

Speaking of white pads, it really isn't a bad idea to have AT LEAST half a dozen of those puppies. You'll find that you will probably use those more than any other pads you have when it comes to different paint systems and removing swirls. They'll both remove swirls as well as work with finer polishes to finish down as well. (At least on harder paints that is.)
Either way, whatever pads you get, you'll want more cutting pads and less finishing pads. So say if you get two colors of cutting pad you'll want 4~6 of each. Simply put, when you're doing paint correction those pads will build (and hold) heat longer. You do not (especially with the 3401) want to try and do an entire vehicle with 2 pads. Heck, I'll use 2 pads for the HOOD! (With a GG6 or Rupes even.) Same thing for the roof. Good rule of thumb is 1 pad per panel. Not to say that you cannot pull a pad off and let it cool while you're working with another one. Just that you don't want to try and do the whole vehicle with 2 or 3 pads without pulling them and letting them cool (doing a rotation along the way).
Move to finishing pads (at least 2 colors of those as well) and you can get away less finishing pads because they don't build up as much heat as the cutting pads do. Not hard to do the entire hood with a single pad with a finishing pad. For that matter it's easy to do the entire vehicle with 2~3 just have to make sure they don't heat up. (
Check for heat on the BACK of the pad, where the Velcro meets the backing plate.)