I've been holding off upgrading to El Capitan, hoping VMware would fix multiple monitor support.
You have a long walt ahead of you
OS X articles
http://www.makeuseof.com/tag/essential-tools-tips-working-multiple-mac-monitors/
and
http://www.howtogeek.com/180677/mission-control-101-how-to-use-multiple-desktops-on-a-mac/