Government clouds (G-Cloud) - Security through Obscurity?

We are currently carrying out an R&D project about applying policy automation and ObjectSecurity OpenPMF to cloud. Interestingly, government cloud initiatives worldwide seem to keep their information assurance (IA) architectures confidential (maybe even classified?). For example (just to name one), the UK Cabinet office published a number of G-Cloud documents but deliberately did not publish the Information Assurance document. I have been in the security field for way too long (over 15 years) and have heard and seen evidence over and over again that security through obscurity's disadvantages outweigh the benefits. And I am apparently not the only (e.g. concerns voiced here) one who thinks that related to G-Cloud. G-Clouds are large, interconnected IT landscapes that rely on standards and frameworks. How is this ecosystem ever supposed to come together if it is hidden under a cloak of obscurity? And how is the required innovation supposed to come in if the cloak of obscurity prevents innovators to apply their solutions to G-Cloud? I believe that general government cloud architectures should be publicized so that the expert community can provide suggestions. It is also a good way to achieve some transparency about procurements and push for standards.I would be grateful if G-Cloud initiatives could provide me with information about their IA architectures so I could explain why and how model-driven security policy automation and compliance automation should be integrated.