Alshon Jeffery or Tyler Lockett in my flex? Devonta Freeman or Marlon Mack?

Start Alshon Jeffery or Tyler Lockett in my flex? Full PPR

Start Devonta Freeman or Marlon Mack vs Houston? Full PPR RB 1 already played Bilal Powell.

I also have John Brown on the bench. Should I consider starting him in that flex spot as well? Already have Sterling Shepard and AJ Green for my WR1 and WR2.

Thanks