The great thing about building walls with a random natural stone material is that you have many creative options. Blocks or bricks do not afford such choice. With walling you are not confined to a continuous repeating pattern using the same shapes all the time. This is the 'on the other hand' method of building. Variety is the spice of life and all that. What a pleasure it is to have to make creative decisions with every stone you pick up. I could use this OR then again I could use that shape. I suppose you could do that with bricks but it would be bit silly.
The choices that one has on hand when walling are one of the most important aspects of this craft. Just as it is neccesary to have a wide spectrum of grain sizes in a good lime-mortar sand, a good selection of sizes and shapes in the wall ensure many and various connections between all the stones in the wall.
If for instance, I was building a wall with a lot of the same size cantaloup shapes, these individual stones might touch their surrounding neighbours in perhaps 6 or 7 different places, whereas if I introduce some lemon wedge shapes and some smaller banana shapes I can improve the proportion of connectivity and therefore congeal everything like a dense fruit torte .
Just as healthy bodies need a balanced diet of fruit and vegetables, legumes and grains (this is the NEW Four basic food groups, by the way) a good healthy wall needs a variety of sizes and shapes of mixed minerals and rocks to build strong healthy walls.
Happily, there usually is this kind of varied stone selection to be found locally over much of the geological regions of Canada. To have the same sized stones shipped in from far way on pallets to your walling job is not only inefficient and wasteful it goes against this basic concept of walling, which is making sure there is an abundance of different choices of shapes. This variety is there not just to accommodate a practical and structural construction but also to ensure we will be looking at beautiful and interesting walls when we are finished.