There were 10,000 Jedi at the time of the prequels, so I guess there were about ten billion clone troopers and a goddamn amazing number of droid factories shitting out enough metal cannon fodder to build a thousand Death Stars, all fighting roughly 5,000 simultaneous battles across space. (since we only ever see 1-2 Jedi at any given battle)
Within 20 years the Jedi were all dead.
Not bad work from Palp considering the galaxy had been a peace for thousands of years and then *poof*.
ronburgandy.jpg
I guess not having Jedi on the battlefield means they are going for a sort of WW1-esque vibe where weapons are so powerful and tactics so outdated that war is an absolute meat grinder. Plus, don't forget the major switch from clones/droids battling it out (who gives a shit?) to real people fighting and dying and shitting their pants throughout. Maybe we'll even get a bone tossed in as to why Stormtroopers went from clones of the most badass warrior in the galaxy to a bunch of inept conscripts (saving money as resources shifted to Death Stars?)
Given the time period, they could have cameos from anyone or no one. But they could do all kinds of things to bridge the gap between the shitquels and the originals. Robot vs clone was cartoon violence, now they are fighting real war.