Unfortunately in starting characteristics of commanders there isn't enough logic.
Many commanders and the major countries and minor had no fighting experience. And were often frank weak commanders. And they are given 3-4 stars.
Why at Zhukov at 36-39 5 stars? If there were 3 stars, and it will be level up over by 43rd year to 5 that ok.
And Model has only 1 star. Though he was one of the best German commanders in defense.
In the Rzhev battle of the USSR I have lost about 2 million people, Germany about 400 thousand people.
From the USSR there was Zhukov, from Germany Model.