Rather than use flesh-and-blood warriors, the Separatists prefer mindlessly loyal soldiers that are easily controlled. The soulless ranks of their armies are dominated by tall, thin B1 battle droids built as mechanical imitations of their Geonosian designers. Battle droids can be controlled by centralized command centers such as the Trade Federation’s enormous Droid Control Ships, or programmed for independent action. They often suffer programming glitches that manifest as personality quirks. Battle droids are dim-witted and no match for clone troopers or Jedi, but they weren’t designed to be smart – they were designed to overwhelm Republic civilians through sheer numbers, something they do very effectively.
At the time of their introduction, the Republic clone troopers represented the future of galactic warfare. Far superior to battle droids, the clone troopers formed the backbone of the Republic's new military that waged war against the forces of the Confederacy of Independent Systems. So symbolic were they of the times, the galaxy-wide conflict that saw their debut took its name from their ranks: the Clone Wars.
General Grievous was a brilliant Separatist military strategist and a feared Jedi hunter, known for his ruthlessness and hacking cough. His body itself was a weapon, allowing him lightning quick strikes and devastating blows. But he was also quick to run from a fight, a tactic that worked until one final meeting with Obi-Wan Kenobi.