Free engines for cross-platform RTS games.

Are there any good engines for a sprite-based 2D real-time strategy games like C&C or Starcraft, preferably scriptable with Lua or Tcl or Python?

I looked at Stratagus and was unimpressed because it is confusing and inscrutable and has shitty documentation.  But maybe I'll have to reconsider if there are no other options.  Spring looks better from the developer's point of view, but it is 3D, and I can't 3D-model for shit.

I want a 2D engine because I can create physical models from inorganic garbage and glue (which is somewhat hard but yields good results, see Starcraft, Doom etc) and make 360° photos of them isolated on white background (which is easy if you have a photo camera and a rotating stand).

>>5
That's why I do high level system models for the system and then do detailed models in the areas where I want to work. Models allow us to focus on certain aspects of the system so that we don't become blinded with information inside source code.

While I could make detailed models of these systems, I usually can't afford the time to work like that. For a system of that size (400kloc of a system using C++) I would budget no longer than one day to complete the high level system models. I budget one more day to do detailed models of the specific areas where I want to work. While I skip over many details in my models during this process, it's easy enough to update the models whenever I need it.

I do this work every time I pick up projects that don't have this sort of documentation. Going through this process means that I can quickly get a good overview of the system and get enough information to focus on my area. If I need to change my focus to other areas, it's simply a matter of filling in the details for my existing high level models.