I have our server set with dns, does this not update if the ip changes?
I have added a new server and claimed it, this merge function doesnt allow me to merge the servers. Any other options here or is the history lost?

If a server has a DNS address entered for its page, GT will check the DNS daily to see if the IP has changed. If the server is unable to be scanned, GT will resolve the DNS more frequently. If the IP does change and there is a server online at the new address, it will change as long as there is not a conflict (ie. it is on the site).

The migrate stats function will only wipe one set of stats. You go to the old page, select the server you migrate stats to, and once you Migrate, the stats of the page you are on (old server) are on the new server. As the instructions tell you, its a replace, not a merge.

The migrate option only transfers historical player stats, not rank. DNS changes transfer both.