I believe you can only have a single fixture path and I was originally going to have node fixtures.  So it was either symlink the fixtures i need, or add node fixtures to the base app.   I ended up not writing any fixtures for nodes though.  So I could undo all the symlinks, although if i ever did create a node fixture (which i very well might do), i'd have to re-do all the symlinks which would be very hard since they are a certain subset.