Even launching multiple processes to stop services "concurrently" will never force them to halt at the exact same time. Services generally run on a polling basis and may be in different states when receiving the shutdown/disable signal. And you generally want them stop gracefully rather than interrupt whatever they're currently doing.

I wrote a utility that iterates over production items and disables or enables them, selectable by host type or name pattern. It will optionally defer updating the production status until all enable/disable operations are complete and it runs pretty quickly doing that. However, the business hosts shut down gracefully, and that may vary in duration. There's not really a good way around that.

If you're interested in the utility, I'll dig it up and share it.