Introduce deliberate variety into a defined set of system components so that a single working technique cannot spread unchecked across the estate. A homogeneous mix of hardware, software and firmware is cheaper to run but lets one proven exploit replicate on every identical instance, however many there are and wherever they sit in the architecture. Organizations therefore choose the components where heterogeneity earns its cost and diversify those, for example by running different vendors at the server and endpoint tiers, tunnelling one vendor's VPN inside another, or relying on address space layout randomization to vary otherwise identical builds. The aim is to raise the adversary's work factor and blunt common mode failures, including those arriving through the supply chain, not to maintain every product in duplicate.
NIST SP 800-172 3.13.1e is one control. If you already hold one of the frameworks below, a reviewed crosswalk already says how much of NIST SP 800-172 your existing evidence covers. Hold NIST SP 800-53 Rev 5 and 24 of 35 NIST SP 800-172 controls already carry evidence.
Each report names every control your existing framework evidences, every one it does not, the reasoning behind each claim, and the claims that were argued against and rejected. 5 were rejected on the NIST SP 800-53 Rev 5 pair alone.
The graph holds this control, the 0 it maps to, and the evidence behind each claim, over MCP and REST.