Honestly I build around what my server is mostly. For instance kage brought a huge surge of lightning players as if there wasn't enough, so I went wind. Knowing that about your server can give you a somewhat advantage in sage and build a team around that.

Are there alot of passive field barrier ninjas? Then maybe use a turn 1 barrier ninja to counter them. Just simple mechanics can help a lot.

I may be wrong but I've felt that 2.0 has changed it to where not a single team has been superior so far, it might be strong in one aspect against one team but another can beat it in a form of rock paper scissors. This is just my view point form server 1 with a lot of Premium Players. So observe what everyone else is in your sage battlefield most of the time and build a team around that. You may not win every match but it sure as heck will improve your chances of winning far more often.

But as more ninjas trickle into the game there will ofc be some teams that are just annoying and downright sickening cool and scary, but for now I see it as rock paper scissors.