My take is quite cynical on this.. This post reads to me like a post-justification of some strange newly introduced behaviour.
Please order the answer in the order the resolutions were performed to arrive at the final answer (regardless of cache timings). Anything else makes little sense, especially not in the name of some micro-optimization (which could likely be approached in other ways that don’t alter behaviour).
The DNS specification should be updated to say CNAMES _must_ be ordered at the top rather than "possibly". Cloudflare was complying with the specification. Cisco was relying on unspecified behavior that happened to be common.