X2 what he said. You can arrange the two poles with the same polarity, the next two with opposing polarity, and so on... but you'll want an even integer of pole pairs. This is done in some PM machines, but the # of stator teeth are pitched to minimize cogging torque (and optimize performance).The normal construction is alternate polarity of field poles, unless interpoles are involved, but usually there would be either 4 or 8 total if interpoles were used.
Max.