I do not quite share your point of view, and here is why. When you have to buy military materiel, it has to meet your needs, and it is not clear that a single supplier can fully do that. Suppliers do not necessarily have everything in their inventories. So you have to deal with several suppliers. How you deal with them is up to you.
In the document you have before you, in fact, I say more about the way in which you can deal with those suppliers and work with them. As for knowing whether there are several sources for acquisitions, indeed there are, and I think that it is up to each country to proceed along those lines according to its needs.