In the crew list I see the rank of the F/O as capt also. So two cpts and one F/O on her first, or training flt.
I have flown enough with two cpts but both need to do some role playing iso the normal way of behaving is my experience.
Only once I experienced it as a burden, however that was not about a safety issue, but I was a little disturbed the rest of the flight which is of course not optimal.
It will be one of the many issues in this accident that possibly contributed.