Not sure if anyone has thought of this scenario:
We loose to bayern,then beat roma - that's us on 5 points
Roma draw with CSKA,loose to us. - that's them on 5 points
CSKA draw with roma,loose at bayern - that's them on 5 points
In the head to heads that would prevail we have all lost one,won one & drawn two against each other ,ie
City v Roma (d),roma v city (a) head to head city go through on away points
City v CSKA (a),CSKA v city (d) head to head CSKA go through on points
Roma v CSKA (h) CSKA v Roma (d) roma go through on points
Therefore who would trump who ???????