Establishment of identity is something I think Leverkusen has done already by virtue of their performance in the last season that got most persons really surprised in the fact that they were able to achieve that much when they were even not rated as a big tea or even a team that is somewhere close to been seen as a big team, this season Al they will have to so is to maintain a statue co or possibly improve in getting to bigger height if possible as that is the best way for them to be able to achieve as much as possible.
In my opinion, one season still cannot mean that they can be said to have a playing identity, because it is only one season while the competition will continue every season, so they need a long time to emerge their true identity. Moreover, they have just tasted the Bundesliga title for the first time, so in my opinion we still have to see how they do next.
Maybe if the teams we are talking about are Bayern Munich, Real Madrid and teams that are used to winning titles then we can say they already have an identity. In fact, in my opinion, now they are in the process of getting this, and whether they succeed or not, only they themselves can do it.
But at least we have seen Leverkusen in very good condition now under the coaching of Xabi Alonso. Now their task is to maintain the consistency of play they have shown this season. It's not an easy thing, but I think they can do it.