that's not what I mean.

They are two options, and both come with their pros and cons.

To file additional I-485 could speed up your cases, because no one knows when INS is going to adjudicate his current I-485. Some people stuck in this stage for years, and only 6 month security in job is far far not enough! So in this regard, you guys should file one more.

But... to have two I-485 cases sometimes cause complications too, especially they are in different service centers. INS needs to consolidate your cases before they finally give the approval, and because that is communications between service centers, sometimes that takes months.

Hope it helps.