Professionals would tear it out and start over..
Grinding exposed ag will surely loosen some of the embedded stone and leave you with even more pitting.
In my area, we use concrete with the stone mixed in. Pour the concrete, screed it off, finish the edges and form our expansion joints, then when it's hardening, wash it down with a push broom and a water hose. A little muratic acid wash when done and it looks very nice. When sealed, it looks even better!