Scenario A. Everyone is equally poor. Let's say each person has £1 and there are 10 people. So the total wealth is £10.
Scenario B, There are 8 poor people with £1 and 2 rich ones who have £5 each. A total of £18.
Scenario B is therefore richer on aggregate than scenario A.
In scenario A, there is £10 and 10 beers, the price of beers is therefore £1 and everyone can buy a beer.
However in scenario B, there is £18 and still only 10 beers, so the price of beer is £1.80. Here, only the rich can buy beer and they can buy 2 each and have change. The poor on the other hand stay thirsty.