Frank Lloyd Wright used stones that were not good for laying traditional stone walls when he built his school out west. The stone was
local and cheap, but it was porous and could not be cut. He made forms, laid the stones along the edge of the forms as he poured in cement, filling the inside of the forns with as much rock as he could to save cost. By placing the rocks along the outside edge of the forms he got a produce that looked like laid stone. He used this process to make beams and small walls. I am sure you can find something on line about what he did and how he did it. The path idea sounds like a good one, and it would be
alot cheaper than trying to form concrete walls and placeing the idividual stone along the forms as you pour. I guess it all depends on what you want, and how much small stone you have. Good luck