Great, thanks for the advice. Will probably try a new game while implementing your strategies. The first try was... a disaster (Soviet on 105). They broke through the lines of the 9th Army in on the shoulders of the Kursk salient just south of Orel (had pulled XXXXVII Panzer Corps to the Zusha, 12th Panzer Division to 2nd Army and 4th Panzer near Bryansk to act as reserves), gaining a total of 6 hexes. In the South the Reds gained 2 hexes from 6th Army. But a though going was the area of the 2nd Army. Just north of Sumy the Red Army opened up a 3 hex gap and South of Sumy the lines of 4th Panzer Army was broken. Now, the situation is not hopeless. In the area of the 6th Army I have already positioned Reich and Totenkopf, making this area relatively safe, while in the middle part the Soviets just don't have that many units to follow up the breakthrough (yet), but it is definetely not the opening turn I wanted.
Well, lessons... first breaking down mobile divisions into regiments to get more reactions is a good idea (although I dislike it, hate so see a 10 CV panzer division get broken down into 3 CV regiments). Second, don't disperse 9th Army assets too quickly, the Central Front south of it is plenty strong. Third, strengthen 2nd Army with mobile units until I can fill this area with more infantry divisions, too many regiments there. Fourth, first go with a normal 100 morale Soviet (I play the 41 scenario with a 110 Soviet, so I though I could manage 43 with a 105 one, guess I still have much to learn ). Fifth, the retreat losses thing is ridiculous, tough to see a unit losing 20-30% of its troops when retreating, roughly the same amount (or even more) as the attacking Soviets, which is absolutely not representative of the reality of 1943-44.