YD - the service guidelines state that one person is to stay down the back and deal with the masses whilst the other 2 are at the front in club.
And as for pouring it takes all of 5 seconds and it cuts down on the massive amount of wastage all these single bottles will provide. I know aviation isnt the most environmentally friendly of industries but i'd like to think that sometimes we can reduce the amount of waste we generate instead of increase it.