I think it would matter what the Universe is for their environment. A UUID may be fine as "server123" if there will never be a collision in their environment (ie. server124, server125, server 126, etc).
a1, a2, ... aN for serves 2 cores 8GB ram
b1, b2, ... bN for serves 4 cores 8GB ram
c1, c2, ... bN for serves 4 cores 16GB ram
...