More info from a source recently returned from the theater...
His comment was that the Army were entirely too predictable. They flew along the same routes at 500' agl, in tight formation a lot of the time.
He cited several examples of Army helicopters that had been shot down where they had been flying and turning over the same point on the ground for several days.
Navy and Marine helicopters were grounded if their countermeasures were unserviceable, where many Army helicopters didn't even have countermeasures...
Evidently the Army general in charge of aviation wouldn't let his people fly below 500' because he was certain he would lose more to flying into the ground than to enemy fire.
This particular individual said they never went above 50' agl unless it was to cross power lines....
Hope that helps return this to the subject at hand.