I think you're pretty much correct. Whether these details matter is entirely application-specific, but you can go the extra mile if your application requirements demand it.
There are certainly multi-core MPUs and MCUs with a mixture of cores. The i.MX series from NXP have multi-core A7s with an M4 core for realtime use. Some of the ST H7 MCUs have dual M7 and M4 cores for partitioning tasks. There are plenty of others as well, these are the ones I've used in the past and present.
There are certainly multi-core MPUs and MCUs with a mixture of cores. The i.MX series from NXP have multi-core A7s with an M4 core for realtime use. Some of the ST H7 MCUs have dual M7 and M4 cores for partitioning tasks. There are plenty of others as well, these are the ones I've used in the past and present.