I'm generally struggling with coming up with the nature of the opposing forces in the Clone Wars. While you can easily explain the Republic armies turning into Imperial forces (and some into Rebels) its tricky to figure out exactly what happened to the other side.

Were they all wiped out? Banished to where they came from? All separated from each other, and placed into individual custody within the Republic? And if any of those are the answer why aren't they ever brought up by anyone minus quick references to the war itself in A New Hope?

The thing is, I'd really like to have some aspect of them that survives in some form into the original trilogy, so that even beyond the rise of Palpatine and the heavy militarization of the Republic, the Clone Wars had an even greater impact than that.

I've been toying around with a concept in my head that the Mandalorians perhaps led the invaders in Clone Wars, but the vast amount of fighters and soldiers were largely pirates and criminals on the edge of the galaxy whose numbers were inflated by cloning. Plus that ties into the decay of the Republic as it was the Senate's inability to enforce law and order in those territories that allowed such a dangerous force to rise up to begin with.

When the Republic does win the war, the Mandalorians are largely wiped out, but much of their armies desert and eventually end up in the Republic planets, most of them becoming criminals and bounty hunters, as there's little chance they'll find legitimate work once their past in the war was discovered.

Thus while there was some underground criminal elements (smuggling, slave trade, illegal spice runs) in the core worlds, the number skyrockets in the years after the Clone Wars, and many of the crapsack elements of the galaxy circa the Original Trilogy can be traced back to the Clone Wars.

Again, just something I've been toying around with.