Pro barb villages in Nakumal and Yaxuna will go away after the merge. As stated in the announcement:

We regret having to do this, but it's a necessary measure to move forward with the merge.

We don't have an official guide for that, there are several strategies that you can go about. It's best if you ask other experienced players about it, join a tribe once the merge is complete and you'll hear about it soon enough

That is another unfortunate but necessary change in order to make the merge viable. I understand it will take some time to get used to it, but we can't speed up the server for now.