Evicting Erika is not smart. You're suggesting it weakens the field for the final HoH competiton and gives Janelle an easier path to the end. But then she has to choose either Will or Boogie who she probably can't beat.Obviously, if Janelle does not make the Final 2 it does not matter. But Janelle can't expect any of Will, Boogie or Erika to bring her to the final 2 with them. If she wants to be around next week, she will have to win the next HoH herself. Why should she fear Erika particularly in that competition? She has beaten Erika (and everyone else) black and blue in these competitions all summer. She should feel pretty good about her chance of winning the Final HoH against whoever she faces.
She should be thinking ahead to that competition and deciding who of the remaining three she wants with her at the end. I believe the right choice for her at the end is Erika. She can leave herself that choice and evict Will (smart) or give it away and evict Erika (dumb).