With a central pack arrangement, each head has a cable that brings the power from the central pack (rather than being self-contained, as a monolight). You may have two or three heads running out of one power pack, which means that if the heads are at some distance, you will need extender cables for each head, which are proprietary to each brand of light. This gets expensive, and it makes location shooting problematic unless you have multiple power packs.
In my studio, the monolights are mounted on rails, so I had my electrician pull a u-shaped circuit over the rails. That way, there is always a power outlet within three or four feet of the light. It would be nearly impossible to rig this up with a central pack and heads.
Penn is a great choice for simple lighting. He used an intensely bright tungsten setup in a large box. It's simple, but dramatic.
Avedon's setup depended on his projects. For his fashion, he used a strobe head on a stick, which his assistant would hold like a boom and move as the model moved. For his studio portraits on white, he used four lights on the background and then one or two for the main light. All of his "American West" portraits were done in open shade and then overdeveloped for contrast.