Multiple co-defendants do not have to be arraigned together. This happens in federal court, especially in multiple co-defendant cases. You need an experienced criminal defense attorney that practices in federal court in your federal district. These are serious charges. Get counsel, separate from the co-defendants, to represent you.
I am trying to give you a general answer to your question. We do not have an attorney-client relationship by this response on the avvo website. I have not been retained to represent you. I am licensed to practice law in Kentucky and in federal court in this state and the Southern District of Indiana. You need to seek legal advice from an attorney licensed to practice in your area..
Like my colleagues answered, No. There could be any number of reasons for different arraignments such as co-defendants are being held on state charges, they may be in other federal districts, etc. You need a lawyer.