Before you try to scale up to 13 tiles, let's make sure we can get tile 2 working correctly first.
It's true that you can try replacing tile 2 DS2DB and DS2Web VMs by cloning from a different tile, and retry. When you are testing the DS2 workload on tile2, please make sure it is a full length 3 hour run.
When you have a run with errors, please upload your zipped results file, which will help us troubleshoot more quickly. The results file contains debugging information that we need to troubleshoot your problem.