Fall of the Republic Announcement and FAQ

[Lord Xizer]

Grievous the murder machine from Legends with his Magna guards(not the lame derp version from the CGI cartoons)
And Dooku in all his dark political glory!

[rednax]

Despite people hating on him, Mauls Shadow Collective is the closest thing to a real third faction that the clone wars ever got (correct me if I'm wrong) despite the fact that it fell pretty quickly after Palps got involved (if I remember correctly).
The only other major faction that I can think of is the Hutts, and they were included in the Collective anyway. While the original release should probably just cover the republic and CIS, I reckon the Shadow collective is not a bad idea.