Optimum Bone To Water Ratio For Pork and Beef Stocks
I don't think you have a problem here. If you find yourself with a rich stock but your recipe needs something gentler, you can simply dilute it as necessary.

When making stock, I follow Hugh Fearnley-Whittingstall's methods (from his Meat book):


Use as much bones as you can reasonably fit in the stockpot; break them up with a cleaver if necessary.
Include vegetables: onions, carrots and celery are the classics, but some others also work e.g. switch parsnips for carrots to give a paler stock.
Pack the stockpot with the bones and veg until it's mostly full, then cover with water. Use enough water to cover the ingredients, but not much more than that.
Bring to a boil and simmer.
When simmered, strain the liquid and bin the remaining solids.
With just the stock, boil it hard to reduce it down to a smaller volume of richer stock.


I reduce mine until, from a large stockpot's worth of stock, I have as much liquid as fits in a single icecube tray, freeze the cubes of stock and keep them in the freezer in a plastic bag for when I need them. Then, I just dilute to taste if necessary; for example if I want a light stock for cooking rice then just one or two cubes to a litre of water works well. If I want to enrich a stew, I might throw a few cubes straight in.