I recently read an old interview with Stardock CEO Brad Wardell where he described Sins as a multistar version of Homeworld, and also said that he'd like to acquire the Master of Orion franchise and make Master of Orion 4 as an updated turn-based game.
Firstly I wondered whether Sins was really Homeworld with multistar? I imagine that this would make a great game, but the core of Homeworld was that it was a three-dimensional tactical game, whereas the battles in Sins are very much two-dimensional. It might be difficult to retain the mobile production of ships and the in-battle collection of resources and have a strategic game component at all, but still three-dimensional fights were essential to the Homeworld experience- along with much tactical subtlety that is simply missing from Sins. There wasn't much 'spellcasting' in Homeworld?
A combination of Sins and Homeworld might still work quite well though. I would have some sort of civil war or mining war set in a giant asteroid field with ancient alien relics hidden in it. The communities would be entirely space-based, so you'd have the Sins concept of space ports, labs refineries floating in space, but do away with the planet element of it, which I always regarded as a weak spot in the Sins game logic. Structures could be boarded as well as destroyed, so you could simply wipe out a community by destroying all the structures, or take it over. The communities needn't exist in set locations, either, though obviously some locations would have advantages. The trading element would be dynamic, you could have agricultural production facilities and solar power plants as necessary to the communities as well. Impenetrable dust clouds could separate the various battlefields- ships travelling through them are undetectable. With a civil war you'd have one tech tree available to all to get rid of balance issues, and reduce the number of assets required so that you can have greater variety of ships. Also, I'd have ship design and naming and experience. Someday someone will have an RTS with ship design. The existing Sins assets would be a reasonable fit for this game, even though it is a very different sort of game.
What Sins reminds me more of is Master of Orion, which also had two-dimensional combat around planet gravwells as the basic element of the game. The problem with Master of Orion, like any turn-based game, is that it gets incredibly unwieldy later in the game- the tactical combat is the fun element, yet you have to move each ship individually then wait for the computer to move each of its ships individually, the fun element is also the chore element. RTS games deal with fleets so much better. Master of Orion 4 as a turn-based game wouldn't interest me at all, whereas as an RTS it would seem to have all kinds of potential. Each a straight conversion using the Sins interface would seem possible, and Master of Orion deals with concepts like invasion, research and spying far better than Sins. The economic element of Sins is far too simplistic, while that of Master of Orion is streamlined enough to adapt well to real-time. Also turn-based multiplayer games always have difficulty with game length.
Of the two designs I've sketched, I prefer the first, it seems to me to combine the best and most advanced elements of two strong games, and to require fewer assets. Trying to match up two-three very different factions is okay if you are Blizzard and there will be pro tournaments and many many games, but for ordinary purposes it would seem better to have a ready-balanced game, it did no harm to the likes of Shogun. Sometimes I've wondered if Stardock is the sort of company that could take a game design and turn it into a franchise, or whether the stronger games they produce will always be hindered by a commitment to a variety of games, and to retro gaming like turn-based games?