An electronic device manufacturing system may include a mainframe to which one or more process chambers of different size may be coupled. A different number of process chambers may be coupled to each facet (i.e., side wall) of the mainframe. The process chambers coupled to one facet may be of a different size than process chambers coupled to other facets. For example, one process chamber of a first size may be coupled to a first facet, two process chambers each of a second size different than the first size may be coupled to a second facet, and three process chambers each of a third size different than the first and second sizes may be coupled to a third facet. Other configurations are possible. The mainframe may have a square or rectangular shape. Methods of assembling an electronic device manufacturing system are also provided, as are other aspects.