Wither and golems always spawn facing south

The bug

When you create an iron golem, snow golem, or wither, it doesn't matter which direction the head(s) you place are facing: the mobs will always spawn facing south.

By following this logic, building the pattern sideways or upside-down should also spawn them in these orientations. I'm obviously not asking for that; I'm saying that at least the directions you place the heads could be respected.