I started a thread on this recently.
I remember him coming on late at Welling (dreadful game) and I was at a loss to explain why his pace wasn't being used to stretch games.
Instead we preferred to play a 4-4-1-1 with Ginnelly on the left and someone out of position (either O'Keefe or Richman) on the right - all so we could accommodate Lawrie in his 'best position' behind the striker. We got steamrollered wvery week.
I don't know if Hednesford have worked out Lawrie's best position yet....it can't be very effective to judge from their Trophy exit tonight at Cleethorpes.
Lawrie did start tonight, when Hednesford apparently had an injury crisis, but he has been on the subs' bench for the last few matches. That doesn't rule out your point, though, quite the contrary.
As for Dylan Mottley-Henry, I think it is as simple as that he is a couple of years older now than when he played for us, and the rest of his game has improved to match his undoubted pace. He is having a superb loan spell at Tranmere.