I hope your searching our archive is helping with your research. I would imagine that the location of half-tracks would be determined by what armament was on them, and the availability of positions which would provide concealment and/or survivability to the vehicle. Certainly a commander would want to include any track armament in his defensive scheme, but depending on the importance of the position defended, might not want to make his tracks vulnerable. Getting his tracks into hull-down positions would be a big plus. Tracks armed with mortars could be placed further back from the line, maybe even out of sight. Tracks with machine-guns could be positioned where their fire would do the most good. Just some thoughts. Best wishes.
John W. Howard