The most important thing is, guard the roads. If you have extra infantry, guard the roads with them, and man the next fort line. Remember to keep some spares in the south in case the Sovs spend a barrage to cross the river. The second most important rule for defensive positions is, always, always fight in forts. Never in the open or even woods if you can avoid it.
Every step counts.
The step-loss rules will mean that the Sovs must spread the damage around all participating units, so their tanks will get ground down. Try to put the KG in the thick of it but don't let them get encircled. Every turn you get two infantry replacements. I love the system. I think the Sovs have an edge, you shouldn't let them factor-count all day.