The part about 'overseers wanting early results' is especially relevant to defense. Program managers need to show progress to keep funding, which incentivizes quick integration of existing solutions over deep technical work. I saw this firsthand when our most sophisticated signal processing work was subcontracted out.
But here's where defense differs from commercial software: When you're building complex systems like radar or signal processing pipelines, the 'buy' approach has serious limitations. You can't just integrate your way to novel capabilities. Those retired experts we had to bring back? They represented irreplaceable domain knowledge that can't be purchased off the shelf.
The tools you mention (linters, static analyzers, requirement tracking) are valuable, but they don't solve the core problem: you need people who deeply understand both the mathematics and the implementation. In my current role, I see PhDs struggling because they lack this foundational knowledge - no amount of process or tools can bridge that gap.
What I think we need is a model that preserves deep technical expertise while still allowing for integration of existing solutions. But the current funding and organizational structures in defense make this really hard to achieve.