It's an issue of hardware differences + some of the software not being designed to be clustered Kubernetes/etc.-style (and it's not mine so I can't just rewrite it).

OK, that makes sense. But why use a platform that abstracts physical layout when you already have a physical layout in mind?

This isn't really something that I have experience with, hence asking; my issue is mainly not really knowing the tools available, therefore I'm looking in the wrong place.

Gotcha! I hope I was helpful.

Normally in these circumstances I'd recommend BOSH but, off the top of my head, I don't know what kind of affinity can be defined. So it might be another rabbit hole.