Thomas I mostly agree with your view but imo slow films have a natively different contrast than most faster films. Can I mimic the look with faster film by say developing a bit longer or using more agitation sure but it will also change some other aspects of the film longer development to get more contrast also gives me more grain, more agitation supposedly somewhat reduces edge contrast. What I am saying is that you don't get a free lunch if you change a variable you will have to pay for the change.
The slow film will already be finer grained and sharper. We are talking about tonality and contrast.
My personal approach is that if I want a slower film I use ND filters. That way I can keep shooting the same film and not have to worry about things like contrast. Since I only use one film (that is never 100% true, but there is one main film that I shoot 90% of the time), then I can tightly control the outcome by just varying my film processing technique. It simplifies things a lot, and makes life a lot easier in the darkroom come printing time, because I always know what to expect.
So, there are some real benefits to working with as few materials as possible, and just make sure that your technique is getting better all the time, which in my opinion will gain you more in terms of compelling prints than any other way. That's just my opinion, and a system that works well for me. Others may like the idea of having one specific film for every type of scenario, and that's fine too. Perhaps they like the challenge of learning four films instead of one? Maybe that IS in fact what they're interested in and what makes it fun for them?
I'm just pointing out that there is an alternative, and that a film's inherent characteristics is just one piece of a much larger puzzle.