So far, I've been using my regular farming squad for phase 2. Didn't get all the medals for ?-9 yet, and didn't do ?-12 yet either, but for the five maps I did so far, the speeds of my squads seem about right: squad 1: 732 speed, squad 2-4: 500-560 speed. For helpers, I try to pick the ones with speed above 680.
For the rest, it's mostly a lack of stamina holding me up. 80 stamina is quite a lot. Especially because I want to do any SG that may spawn as well.