Barcelona seem to be very lucky been grouped with Porto, Sharkhtar and Antwerp because clearly they are dominating in the group winning all three first legs and leading with nine points with Porto following behind with 6 points. It doesn’t look like Barcelona will lose even a game in this group, their future in the UCL this season looks very promising.
There is no guarantee that Barcelona will always be able to win every match in the group stage even though on paper the depth of their squad is better than the 3 competing teams. Barcelona lost many important players at this time and several players who recovered were not yet fully able to give their best performance. Raphinha, Lewandowski have played today for the El Clasico match, but their performance is still not satisfactory.
The only thing I am sure about Barcelona in the Champions League this season is, they will qualify for the last 16. Of course, that's because they have won 3 of 6 matches, which means they have secured 9 points. It only takes 1 win to ensure they qualify, so it's not too heavy a burden for them.