The question could be made more clearer on what is meant by German perspective. I will answer it the way I understood it, and rephrased in the sense I understood it the question becomes:
"What was the German military understanding of the situation at Stalingrad before and during the battle of Stalingrad?"
Note: German forces in all the text below should be considered as Axis forces since Romanian, Hungarian, Italian and Slovakian armies fought in Fall Blau and during the Stalingrad campaign
Before:
Before the battle of Stalingrad itself, the Germans had a variable vision of Stalingrad and how it would be important for the war.
Initially in Fall Blau (the strategic plan for 1942), Stalingrad was not considered as a specific target. The Don and maybe the Volga were considered as stop-points to establish a flanking defense in order to protect the advance on Caucasus.
When Fall Blau started and met successes inside the Don's circle and up to the fall of Rostov, German high command remained in a similar perspective. The importance of the flanking defense was just enhanced a little bit because of Voronej's difficult capture.
Later on, the fight on the Don became harder and harder, with good resistance of some Soviet armies and massive though poorly led counter-attacks by Soviet tank armies: thus, the flanking defence again raised in importance, but the eventual success led to confidence that more could be taken on the East: namely, blocking ship transport on the Volga and capturing Astrakhan. This goal required taking Stalingrad.
Again, later in the summer, the Caucasus front faced difficulty in taking its final objectives: the Black Sea coast resisted, some oil fields were taken but found destroyed, and some were unreachable. Losses started to rise in mountain fighting, logistics there was in difficulty and Fall Blau was about to fail in meeting its target. Because of that situation, in all German high command, including Hitler, Stalingrad became the new target with three reasons for which the city was found useful:
- Block oil shipping on the Volga
- Allow further progress to Astrakhan
- Later in 1943: prepare next strategic plan which would iterate Fall Blau in the Caucasus
Because of that, new efforts were put in to reach the city of Stalingrad, notably with the all-in attack of the 6th Army and the 4th Panzer Army. Note that heavy Soviet resistance was met and that this led to problems in achieving the target.
During:
During the battle of Stalingrad, the Germans made three mistakes:
- First: They did not fully understand that urban fighting would be that difficult, and even if they tried to adapt tactically, they never considered that the timeframe was enlarged and that their strategy should adapt as well, which means the strategy should considered the fighting was to continue in winter 1943. Propaganda was reflecting the thinking of German command when it said all the time that the "final offensive" was about to be launched, that Stalingrad was "almost taken", and so on
- Second: Their adaptation was only tactical (they brought on heavier assault guns for example), but it did not include further air interdiction of the Eastern shore of Volga. Note that such an action was difficult because the Eastern shore was partly covered with forests, through which Soviet reinforcements came in
- Three: Because of the Soviet constant harassment on the North flank of the 6th Army through failed counterattacks led by Jukov, and because of the action against Rhjev salient, German intelligence failed to consider the multiple "little reports" of local German, Italian and Romanian commanders posted West and East of Don and who were subjected to Soviet attacks preparing the counteroffensive
Eventually when the Soviets succeeded in the initial counter-offensive, German high command was always late in understanding its full potential. To put it in a comical way:
- Germans think the Soviet counter-offensive will be blocked, but it achieves circling of their troops
- Germans think their 6th Army will liberate herself, but the Soviets block her
- Germans think the Soviets had sent all their efforts in, but by continued attacks the Soviets break their efforts to re establih a front (destroying by the way an Italian and a Slovakian army)
- Germans think a counter-attack will save the 6th army, but the Soviets block her and thus more of German troops are in danger of being trapped
Conclusion:
Because of initial successes and 1941-like failed Soviet tank counter-attacks, the Germans were encouraged in thinking Fall Blau would become a big success. As long as elements piled on stating that there would be problems, the Germans failed to acknowkedge them in time. Frustrated of the failure of their initial objectives, they started to focus on Stalingrad. Again, this focus lessened elements stating the Soviets were still an offensive power and thus the Germans failed in reinforcing and defending themselves correctly.
As a sidenote, a similar process had occurred in China during the battle of Taierzhuang which saw a Japanese defeat.
