Hello!

10 to 20 newest servers would mean 10 to 20 weeks more or less than your server and during that time span, players from those servers would be likely to have a better ninja already so the thing about being much better and balanced is nothing. However, if your server is still within 50~60 days, it should still be a local-server matching only, which means that you should only get matched with someone within your server. Although, in some cases, players from those servers will get matched by a system-generated team that makes players think that it is already at cross-server matching but it is not (if the system detects no one is playing in your server, this will trigger it).

The arena is such a pain and struggles for newer servers at the beginning phase of your gaming but it will be better once you progress in-game by having enough good units to use for battling. Together with your upgraded initiative and a good strategy, you'll be guaranteed to get a possible chance to win a battle. Thank you.