Hi Maurice,
Good question, your coach is right there in that keeping the ball low does help avoid players counter attack. Ideally low and deep to the table is the optimum placement. I think this advice helps all players, but what is important is to not worry to much about this for now and and focus on your quality of shot… is your shot spinny, consistent and good placement.
If you could send in some videos of you playing your shots that would be great to analyse 🙂
Talk soon,
Dan