Badass Normal: The Sisters of Battle do not have access to the Warp/Force nor are they enhanced like the Space Marines are.
Bad Boss: Dooku shows just how little he actually cares about the Confederates he rallied to his cause when he leaves the Separatist council to die on Raxus Secundus simply for not agreeing with him about the truce with the Republic.
Badass Army: The Republic has the Clone Troopers and the Jedi while the Imperium has the Imperial Guard, Sisters of Battle, Skitarii and the Space Marines.
Individuals within the Republic also have their fair share of mechanical limb replacements with characters like Echo and Anakin Skywalker, however such practices in the republic are far more humane and less pervasive compare to those found in the Imperium. Special notice goes to the Adeptus Mechanicus and their religion where everyone is expected to replace a majority of their bodies with mechanical parts.
Artificial Limbs: Shown in massive numbers in the Imperium, coming from a galaxy in perpetual war, many soldiers have replaced their limbs with mechanical parts due to past injuries or to personally enhanced their fighting capabilities.
Whether it's justified or not, often times the local populace would see both armies in a bad light and not wanting to be part of the galaxy wide war.
Same thing could be said to both the Republic and CIS armies especially from the viewpoints of neutral worlds.
Not to mention the trope on top of the Imperium clearly takes the cake for evil armies in this story.
Unsurprising that the Imperial forces are portrayed as this, after all, any faction that comes from Warhammer 40K would easily be the main villain in any other franchise and story.
An Arm and a Leg: Crosshairs losses a leg to a Space Marine.
The Alliance: The CIS and the Republic form one to combat the Imperium of Man.
Such policies are shown in all its horror with the Imperial conquest and occupation of the Axum system.
Absolute Xenophobe: The Imperium of Man has absolute xenophobia as a matter of official policy, and the Imperial Cult preaches the supremacy of mankind, and the extermination of all non human races.