Dancing chacarera in a line is a better experience than dancing it only as a couple. (though strangely enough i don't feel quite the same way about zamba - it is structurally similar, but much more a couples dance). The folk dancers i have seen seemed to tend to create smaller huddles when the dancefloor is to big for the number of people they have, not separating them wider.
Well, I am not sure that chacarera and other folk dances with fixed sequences are really relevant analogies. The shared connection in these dances happens precisely because everyone is doing the same thing and most of them would look really stupid if only 1 couple was dancing.