If your parent company sysadmins invest heavily into automation each sysadmin could be managing thousands of servers.
Also, 6000 CPU "cores" on the cloud is more like 3000 CPU cores. Which you can get in just 20-50 servers. This is in the range of something that could be taken care of as a part time job.
Also, 6000 CPU "cores" on the cloud is more like 3000 CPU cores. Which you can get in just 20-50 servers. This is in the range of something that could be taken care of as a part time job.