PathGeometry and CombinedGeometry Issue

1. Given 2 PathGeometries (pathGeo1, pathGeo2) which represent 2 disjoint single line segments and are returned from a call to GetWidenedPathGeometry;
2. I create a combined geometry, e.g.
CombinedGeometry combinedGeometry = new CombinedGeometry (GeometryCombineMode.Union, pathGeo1, pathGeo2);
3. I flatten the combined geometry into a series of points, e.g.
PathGeometry pathGeometry = combinedGeometry.GetFlattenedPathGeometry();
4. The result is far too many points regardless of the tolerance setting in either GetWidenedPathGeometry or GetFlattenedPathGeometry;
5. Is there a better way to create unions and intersections between paths?  Or is it possible to reduce the number of points to a bare minimum?