Ok so there is something I have been noticing while playing this game. It is extremely dependant on having a large active player base to get the full experience. In my server though, we don't seem to have that. In the great ninja war this week, we only have 3 groups in it. We have never even had a full war before. There is how this game is going to fall, not enough active players to participate in content. So how can we fix this?
Step 1. No New Servers
So this step is simple, stop opening multiple servers every week. I understand that newer servers will attract new players, and also tempt more people into buying things. But new servers are not good for the health of the game. If there are no more brand new servers, then players will be funneled into some of the exsisting ones. There they will be at a disadvantage, but eventually players will level out, and new players will be able to catch up. As well, exsisting groups will be able to bolster their ranks with these new players.
Step 2. Merge Servers
This can be tricky, because there are a lot of problems that can arise. So if this does happen I would suggest doing these things to make it smoother. Only merge servers with simular power levels. Take the average power of the top 10 players in each server, and then merge servers with close to the same average. This makes sure that weak servers will not be merged with powerhouse ones, and instead of servers getting new prey, they get new compition. Then you have to handle the same name issue. Lets say there are 4 players with the name Naruto, and you are merging their 4 servers into one. Look to see who had the name first, and let them keep it, then for the rest add a number to their name. So we would have Naruto, Naruto1, Naruto2, and Naruto3. Then if a player's name was changed give them a free name change. Do the same with groups.