I think DGDP was originally set up to promote joint-services procurement, offsets, etc, but it wasn't given enough teeth to carry out its work. Even if we accept the fact that our generals make the final decision, they could've still established a joint-services commission to bring the best options forward.
IMO, the Army shouldn't have gone with the HQ-16 as it's an older SALH-based system. Like the PN and PAF, it should've pursued an ARH-type SAM from the start, and that would've naturally flowed into a convo about a joint-services SAM order. That's a big enough order for local production, especially if we bake in plans for a long-range variant, upgraded variants (e.g., improved seekers, ECCM, etc), and future platforms/applications. If not MBDA, I'm sure we could have landed a good deal from Roketsan in Turkiye.