I was playing Dread Lords in a Small Galaxy just 2 days ago when the dread lords showed up right in my backyard. It was an intoductory game, so I was still trying to get the hang of things. From what I can gather, they brought their own planet (and possibly star) with them when they came.
They were only half a sector away from my only 2 planets, so I know that the planet was new. I ended up invading them with 3.000,000 soldiers compared to their 20,000 defenders. I did an orbital bonbardment, and I only lost slightly less than 700,000 soldiers.
I figured that since I had the green thumb ability, there would be no permanent downside to an arial bombardment (I already had Mars to a class 8 or so and Earth was a class 14).
I think the dread lords' planet was a class 11 or 12 after I bombarded and invaded it.
I got the tech for HD Spike Drivers IV from them! This is when the biggest fleet of the most militaristic race in the galaxy at the time (and my next-door neighbor) the Yor had a combined attack of 18. I put three of those guns on a Small-hulled ship. The downside that I forgot about is that it had very little HP. I'm thinking that I'll just put it in a fleet with my Medium-sized ships.