Attempting to add crobercore

I am currently trying to add Crobertech:Core to the eclipse workspace so
I can build my mod on top it without errors. This is entirely
frustrating as I would like them to be separate repositories but still
the same workspace. Git Submodules might be the key to my problems, but
having troubles putting the files in the right places (trying to add
crobercore by gitmodules to the src/main/java/ will attempt to overwrite
the src/main/java instead of adding the packages together)
I could just include a copy of crobercore into the src/main/java and
update it manually