"with just 25 servers"

This really needs to stop. Go to stackexchange.com and you'll find that more than half of the HTTP requests are to cdn.sstatic.net.

Looking up the IP addresses for cdn.sstatic.net returned five entries for me, all owned by CloudFlare. None of the CloudFlare servers that they are using seem to be in that 25 count.

Sure, these are all for static assets, that isn't the point. There are way more than 25 servers being used to serve the StackOverflow sites.