This is a follow up to the question “What are the fundamental differences between the ～と一緒に and the ～とともに fragments?” Someone suggested that I post my question as a separate thread.
Well, something is off for me. It seems that Derek and rcjsuen's answer clash somewhat. If I am being explicit or am emphasizing who I am doing an activity with, this implies that I and this person did everything together every step of the way. However, according Derek's answer, I would use 一緒に. But according to rcjsuen's reply, I would use 共に.
So what am I missing in this understanding?