In college I had a good friend whose family raised sheep. They always had some of their wool carded for batting each year & it made beautiful quilts. The carding process they used alternated horizontal & vertical run fibers so she and her mom & aunt would always just use a single layer of wool that was either tied or stitched together with roughly 1.5" spacing. You can't stitch as far apart with carded wool as with commercial products. I know some people who will needle punch it (either by machine or mechanically) in order to make it more stable, but I personally love the look & feel of simple carded wool.
Those quilts were not washed more than once or twice a year, and usually they were line dried on a warm, partly sunny day after being washed on the gentle cycle in cold water with Orvus soap. I'm saving up to buy a carded wool batting to make myself a queen sized quilt for my bed. It is just the most luxurious product I've ever seen. Assuming the person who made your batts did them the same way as my friend's were made, I think you'd actually have less bunching with a single layer of batting than with multiple layers.