I'd gladly listen about the difficulties of setting up enterprise networks! No irony; listening to experts is always enlightening.
BTW a homelab often tries to imitate more complex setups, in order to be a learning experience. Can these difficulties be modelled there?
company where i work has deployments across the world with few hundreds of thousands of hardware hosts (in datacenters), vms and containers + deployments in a few clouds. also a bunch of random hardware from multitude of vendors. multiple lines for linking datacenters and clouds. also some lines to more specific service providers that we are using.
all of it ipv4 based. ipv6 maybe in distant future somewhere on the edge in case our clients will demand in.
inside our network - probably not going to happen