A modular stator-inverter assembly for an electric machine includes a stator and a traction power inverter module (“TPIM”). The stator includes a stator core having a center axis, an inner diameter (“ID”), an outer diameter (“OD”), and electrical conductors forming stator windings. Stator teeth extending radially toward the center axis from the ID collectively define stator slots occupied by the stator windings. Each adjacent pair of stator teeth defines a respective stator slot. The TPIM delivers a polyphase voltage to the stator windings to generate a predetermined number of stator poles, such that the stator has either two, three, or four of the stator slots per electric phase per stator pole. The stator defines a center cavity and is configured to receive a selected rotor from an inventory of preconfigured machine rotors. The inventory includes multiple synchronous reluctance machine rotors and an induction machine rotor.