Even by the time Sins of a Solar Empire folks Ironclad Games announced their MOBA Sins of a Dark Age [official site] in 2012, the genre was a little overcrowded. SoaDA was originally billed as a MOBA/RTS, but later dropped bits like base-building. It’s still trying to be more ambitious than you average Dote ‘em up or Loller, though.
Now, after a lengthy stretch on Steam Early Access, where it costs $5 (and it was $25 for beta access before that), Sins of a Dark Age is out free-to-play for all to manage lords. It’s on Steam.