>It just happens that there's a lot of commonalities between the different "spread out systems", but there's not necessarily some grand unified definition for all of them.

I disagree. There is a unifying definition, but it requires moving away from design/architecture words like "spread out" and towards subject-object/representation terms like "local visibility".

>The only thing the average person needs to understand is they're complex and error-prone [...]

Agreed, but the topic was standard (implied: universally correct) definitions.