I have already posted here some threads where explained reality of shia call for moslem unity.
Now, just found interesting quote in book “Al-Etikadat” by as-Saduq, page 83.
واعتقادنا فيمن خالفنا في شئ واحد من أمور الدين كاعتقادنا فيمن خالفنا في جميع أمور الدين.
And our belief in those who opposes us in single thing from religious aspects, like our belief in those who opposes us in all aspects of religion.
This is a very important quote from one of the top scholars of imamiyah. If you oppose them in single thing, no matter what is that, is it fiqh or faith, wala bal bara or amr bil maroof, in their view you opposes them in all aspects of religion.