Same as yours. I have grown and am presently growing semidwarf and dwarf fruit trees. I've tried his method; it works. Do the trees compete for resources? Yes. Does pruning them as he suggests keep there production down? Yes. The whole Idea is to keep the trees small and managable with a manageable amount of fruit. If you have a small yard and want a variety of fruit without having to throw or give most of away because you can't use it this is one way to go. If you've got a couple of acres, by all means, spread them out. Just be prepared for all the fruit you're going to get.
The OP was asking if he had enough spacing for his trees. I posted a reference to show that trees can be planted closer than the spacing he had used. Merely that. Last I looked, universities and research stations were much more interested in helping farmers and agribusiness that they were the backyard gardener. You probably don't think much of square foot gardening either, do you?
Bill
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