I hadn't thought of the fact that apache would be architected to use its multiple threads as an internal housekeeping (instead of just to allow parallelization of requests).
My motivation behind moving the processes to be so low is that I'm trying to explore Apache's suitability for use in a Docker container, in the "Docker way" - minimal processes per containers, that, when the process failed for any reason, the entire container is killed, and you spin up many containers to accommodate that. I think this is the point where I give up, and just spend the time porting this app to nginx.