I retired three years later so have lost touch. But before I left a couple of new procurements were starting up, and I attended at least one meeting where the separate customers were in fact in the same room and playing nicely with each other, which was a very good sign. The acquisition authority had also established some cross-cutting functions (design, contractual support) that would in theory support the new projects coherently, when they reached that point.

As my career progressed, I got a better handle on the genuine cultural issues behind some of the customer-level differences. For example, one particular category of user had very different career progressions / longevity in different parts of the overall organisation (heroes in one part, zeros in the other, approximately). This affected the relative prioritisation of the relevant requirements by the respective customers, and the perceived value and affordability of solutions, in a way that overshadowed the tech-focussed arguments younger-techie-me would have made.