All Token Ring networks I encountered were star wired. The MAU is required. In theory you could directly connect two PCs together but for more than two you need an MAU.
here's some scribbles I did when I worked at a place that had TR
The Early MAUs had no electronics in them, just passive reed-relays that opened a connection as the cable was inserted. When you removed a cable the relays shorted the outlet to let the tokens across.
The last one is representative of one floor of a building I worked in.
The 2715s had 16 lobe ports (for PCS) 4 expansion ports (for other 2715s in a stack) and RO & RI ports (ring-out, ring-in) for connecting to other parts of the building. There could be several stacks of 2715s, each serving a separate part of the floor. The RI & RO ports were cabled back to a floor concentrator. The thing at bottom right is a router which, in this case, simply bridged each floor ring to a backbone ring that linked all the floors and the server-room.