Wow, you put 0 thought into this have you....

First, 15 different teams for the arena would be annoying for EVERYONE.

Second, what exactly constitutes a team?

The exact 4 ninjas? Welt, for a 9 tail naruto+healer build, let's rotate through the healers. And maybe let's trade roshi for a different char and rotate through the healers again. That should do it, the 6 tail naruto will probably carry the team anyway, a great help that is.

Every ninja on a winning team gets disqualified? Welt, newer player can't even complete the event then, they have to journey into ranked mode which makes it worse for them.

The first couple hour of the event tend to be bad, there will be people handing out free wins soon enough. Don't come complaining because you choose to play at a bad time and gets mad due to losing. Most ptw aren't evil enough to stomp around training arena for no reason, they gain nothing from doing it and have better things to do with their time.

Totally agree! At least for Ranked the matching is within 10 levels from yours but i dont know if its the same for training as well or not. In general trying on different times per day should give you enough chances to reach your target either for the daily arena missions or other event based target lick the Shibo feast arena training.

I even often find players on training arena who just set their main character alone

Lets say the limitation of 3 days for shinobi feast doesn't help. I still don't understand why they don't just let it be there for the whole week.

I'm one of those rushers praiseluka talked about because, due to the limited time of the event i wasn't sure to be able to complete it within the end of Saturday, if lasted until Wednesday i would have had no problems in just getting 5 wins yesterday and the other 10 in the second half of the event.

They can't do that because it is now on the monthly event where you have to do 5 arena challenges. Plus it's also on the daily practice where you have to do two. There are also other events like Sakuras challenge and the mission dealer where you may have multiple task that could add up to more then win 10xs in the arena as well as the regular arena missions where at times if you do it right you only have to switch out one or maybe two ninjas from your main team. There maybe days where you have to do the arena 2xs a day or 20xs a day. Plus on the training side that's why it's called training...it's practice. You get nothing from it it but a win and some experience. If you quit cause you can't win on the practice side then maybe this game is not for you. The game is about fighting different players and teams. Everything you do in this game surrounds fighting other teams in pvp or pve. There are a lot of free players who compete but the reality of the matter is any game where you are a free player you will never get the same thing or have the same results as a p2w player. The game is someones business and what business do you know can stay a float with either catering or giving away everything for free.

How will they do arena missions then?