Mmmmm, not sure I agree with this. I would have thought that it would be quite difficult to mix all those genres up without the set getting disjointed. I also think single room venues don't have to be across the board necessarily along as they are advertised as something specific.
Soulsville anniversary worked as a night, not because you had a number of DJs all playing ATB sets, but because there was enough diversity amongst the DJs be it 60's 70's whatever. On the other hand I am a forties something diehard