Had a lot of fun with the Polish-Russian War scenario but finally finished up with it.

I am now moving on to the short campaign. I have noticed that both the southern whites and siberian whites have large numbers of troops which are restricted to specific regions. Apparently those troops are very reluctant to fight outside their home regions. Their special abilities state that region restricted units suffer significant penalties when they leave their home regions. What exactly are those penalties? Are the penalties so severe that it makes no sense to risk them outside their home regions?