Star Ruler is a sandbox game, and I think these guys would prefer the constraints of Sins to the bland sameness all the races of Star Ruler have in terms of technology and weapons.
That's the part of the a mod to decide where it goes. The core game has a typical sandbox style but also modding capabilitys are very much sandbox. I'm sure that you could make "defined" races with own tech trees and ship set's just like a custom star map and special conditions.
You could even add the borg to harass the galaxy. Such mechnics are allready in place.
what i'm saying that it's a great toolbox for modders to create their "dream" mod without much headache. Atleast adding new possibilities would have a greater chance because of the high active dev team. In comparision to Sins where you would have to wait a decade to get a specific feature done, it would surely be much quicker in SR.
I wouldn't consider myself a modder but i've started on some small project myself and am revamping the tech tree to my liking. And if a total noob can change stuff that easy then a pro mod team could do it without problems.