The 12 tribes of Israel were separate but still part of God's one people, and part of the family of God. I would consider them more analogous to different traditions in a church (different cultural practices under the same theology), but not denominations (which remain separate because of theological differences, primarily).
Jesus prayed that we may be one (John 17:20-23). The analogy of the Body of Christ (1 Corinthians 12) and being one, as well as the analogy of the vine and the branches (John 15:5) also indicate that we are to be together, and not separated.
Denominations have split off because of human sin in general (with culpability on all sides), and not because it was Biblically appropriate. There was one church in the first centuries. It is because of human sin that people broke away. That is why we pray for unity and encourage interdenominational dialogue and reconciliation.