*** Scenario of the Month: November 2014 - Parings

[A Canadian Cat]

I haven't dealt with Battlefront's support, or ran into any problems with their restrictive DRM (so far!), so I don't know how this would affect their licencing... but would it make sense to uninstall both copies, then install a copy, patched and expanded to version 2, then copy that and install the patch to version 3 on the copy?

Yes. There is an install order that needs to be followed but you have summarized it pretty well. The official word is here: http://battlefront.mojohelpdesk.com/help/article/128133

I hope that helps. CMBN works really well with multiple installs because each version's game files are separate. Once you get the two installs up and running you will be happy I am sure.