Not OP, but here's my take: I have two machines, one with NixOS, one with Mac. I use the same configuration on both. Keeping both machines in sync is a matter of two commands, adding a new machine is also a matter of two commands.

I have tried multiple orchestration options before, but they always fail in some way, ansible for example always work until I have to run something from scratch, then it fails miserably because of something that changed after the 20th time I've ran the script. On Nix, that's not even a consideration.