I know that BA manage with just the Purser in charge of the A321, it seems from the part of the post below that it is being questioned, hence why I mentioned it.
Purser - Junior Swap on 747
This initiative, we believe, speaks for itself and the ramifications for the future are catastrophic. We believe this is the beginning of an initiative by Xxxxxxx Xxxxxxx to remove all but two of the supervisory crew onboard their aircraft.
Promotional opportunities are being removed for our members in XX and this we find unacceptable. A clear example of this can be seen in the imposition of a Purser in charge of the A 321 on EuroFleet