If we ever went to a real war, I wonder how many of our 420 4 Star General Officers and Admirals would ever be in any real danger?
Few of them, but that's a feature more than a bug. The Russian habit of losing flag officers reflects the repeated breakdown of their chain of command, the failure of their army to delegate decision making to front line commanders and their complete lack of a non-commissioned officer corps.
TL;DR: If you have to send a 4-star general to the front, something has gone wrong.
There are 44 four-star officers in the US military. But I agree with your point - they are often far behind the lines. Unlike in the Russian military, however, the U.S. and its Western Allie’s trust their subordinate officers to run the battles. In Russia, the senior officers have to lead from the front. Given their valuable experience and training, such a practice is not bravery, but stupidity.