The knowledge gap in procurement, (how) does it exist?

For some years, I've been working for a multinational project-based engineer-to-order firm in the Netherlands. Among the products we procure, there are many complex goods. However, our procurement departments are organized in a specialized way; for all projects, one officer buys a certain type of products. I have the idea that project-based buying is impossible due to a knowledge gap. Since the goods are so specialized, there is a gap between what a limited amount of suppliers can deliver and what an engineer specifies. This gap only can be bridged by a procurement officer. My question is what your thoughts on this topic are, if this gap exists and whether it could be solved.