Polls show Johnson takes equally from Trump and Hillary. The latest Fox poll has Trump with a 3% lead with or without Johnson.
I am wondering how many Sanders people will go vote for Dr. Jill Stein if she is the Green Party candidate and Hillary the Dem. A number of registered Greens in various states temporarily left to register as Dem. to vote for Bernie. I have listed platform and issues links for Libertarian and Green Parties. The two platform listings for GP show a complete write out of their 2000 platform, and a summary, clickable contents page for 2014. I have not compared the two.
https://www.lp.org/platform & https://www.lp.org/issues
https://www.greenparty.org/Platform.php & http://www.gp.org/platform & http://www.ontheissues.org/Green_Party.htm