Everything you've described, especially what Swift is talking about, is why CA was founded.
A game with a gameplay style similiar enough to other RTS's and OTA to be familiar but different enough to be a distinct game. A base of content that is OTA IP free but is robust and broad enough that people will want to use it to make their own mods from it. A way to divorce Spring from OTA, a flagship mod with which to advertise spring.
We're
really not there yet, mostly because we need heaps more models than we have. But its what the project is about.
I think there is a valid argument in saying that rather than working from OTA and changing it into this new thing, starting from scratch will get there faster. But, if you really want these two different approaches working from two different directions towards the same goals id suggest we cooperate on art assets, at the
least, because this is the bottleneck for our projects.
Info on our Wiki can be found about
Concept Art,
Models,
Graphical Design, etc.
Some of Mr.D's models are similiar to OTA designs, but several are not even based on OTA units at all. There should be enough to use, though Core logos will need to be scrubbed (We will be doing this eventually).
For the Arm/Nova (Tenative new name) stuff, we've gone for a sort of smooth white high-tech look, as in my Spherebots (These have several different texture attempts over their history).

(There are 3 variants on this unit).
The Chickens are also free to use, both models (KDR + me) and scripts (me).
We've also a bunch of other misc models, such as the destroyer, fighter, solar panels, metal extractors, wind gens, etc etc.