>The C layer should be as thin as possible and have logic in it that pertains to routing and whatever kinds of transforms your "wire"/"transport" layer needs while the Services do all the heavy lifting and contain most of the business logic.

I believe Trygve Reenskaug (the inventor of MVC) would agree with this point. After MVC he went on to invent "Data, Context, Interaction" (DCI) [0], which aligns with what you're describing.

[0] https://en.wikipedia.org/wiki/Data,_context_and_interaction