PMDC armature winding machine

For PMDC motor, how many magnets and brushes related to how many poles, for example with 2pole, 16 segments,

The winding is always symmetrical, 

 Use of fractional pitch is not a design compromises to facilitate automatic manufacture and The fractional-pitch type of winding is in general use, because it produces less sparking and because it requires less copper, which means lower armature resistance. Winding pitch is a design compromise, but not to facilitate automatic construction.