Fair enough.
A suggestion -- I've looked over the Spring code in more detail (the actual base C++ code). It's not bad and it's very usable. As I recall your previous effort with Haven involved using a pre-built engine and Lua scripting. That could work but from what I saw I seriously doubt you'd be able to get the Outpost 2 behavior out of units via lua scripts. Very likely the behavior would have to be built into the engine itself.
Structure placement would also have to be modified with an included 'connectedness' algorithm. This can be done relatively efficiently with a depth-first search -- it's the same technique I used in OutpostHD. I would only run such a search in an RTS maybe once per tick (maybe every 2000 - 3500 milliseconds? that would have to be tested) and if possible in a separate logic thread separate from the rendering thread.
Lastly, you're right about failure rate. Sometimes it's not about being ablet to succeed, sometimes it's just about learning. If that's the case, I'd suggest instead of a full-on project just coming up with some sort of prototype that demonstrates the basic mechanics. I made the same suggestion to LordPalandus in
his thread. Still haven't seen much out of it but it seems like he's made some good progress understanding his own limitations and the scope of what he wants to do so basically a lot of positives.