Usually it depends on who the other guys are. Some nights I go there and the men are mainly the arrogant, higher-than-thou bunch who wouldn't get involved. In that case there is a high chance of you getting stuck with a girl with no one taking over. This is, sadly, especially true if the girl is a beginner and very difficult to lead. Other nights you happen to have a lot of advanced, nice and friendly guys who would be happy to joinin.
This happened one time, when a girl's friends stupidly arranged to have a birthday dance but hadn't made sure there were enough guys around, or rather, hadn't correctly read the type of guys that made up that hot night crowd. (That means this was probably Friday but I forget)
Between a birthday girl feeling bad and a guy looking bad by dancing with her, what should one choose? The answer to a couple of us was easy. So we took it in turns to dance with this poor girl, smling and grinning all the way, alternating between me and him. That actually guilted some of the other dancers, even a couple of salsamafia, to join in, and in the end the girl ended up probably with 7 or 8 partner switches. I believe that was the only birthday dance with a beginner where so many high-intermediate and advanced dancers joined in.
It's sad the sort of attitudes prevalent among those who feel they have to be 'cool', or rather have a certain idea what 'being cool' means. But it's also a warning to anyone oraganising something like this for your friends: THINK AHEAD! Get guys/ gals ready who will keep the switches happening.