Before coding begins, the project must define P1–P4. Only then should P5 begin. Until then, GCC architecture will remain implementation presented as architecture.
One side mistakes construction for architecture. The other side mistakes IT inventory for architecture. Both miss the same thing. The actual project anatomy.
At the GCC, engineering leadership can build faster, scale teams, improve platforms, and deliver releases. But if P1–P4 are not explicit, the GCC is only scaling implementation. Not architecture.
The missing work is not more engineering leadership. The missing work is explicit project anatomy.