I had forgotten all about this thread.

I don't know about Brahma but Mara at first got friendly with Itala and there did appear to be signs that both groups might merge (note that this was my observation as a Jedi - the Sith might tell a different story). However some members never liked Itala and in the end Itala and Mara couldn't agree on anything (again, my observation) so the ties were cut and have remained that way ever since.

Some more history for the masses.