This paper studies the value of allowing multiple transmitters to share all of the available bandwidth to concurrently transmit to a single receiver with multi-packet decoding capability. While such coordination can be bandwidth-efficient, it increases the density of interferers when many such multiple-access clusters exist in the network. On the other hand, orthogonal schemes such as FDMA may not be as bandwidth-efficient but operate at lower interferer densities due to orthogonalization. We take the first step towards understanding this trade-off. In particular, we analyze equidistant transmitters sending data using a coordination scheme based on the optimum strategy for a Gaussian multiple access channel. In terms of the throughputs seen in a typical cluster in a Poisson network, this form of coordination has little or no benefit when compared to FDMA. We also find that the increased interference due to multiple coordinated transmissions reduces the efficacy of successive decoding. ©2010 IEEE.