Bayer Leverkusen was built with strong chemistry and Xabi Alonso's tactics are very suitable to be applied with the existing player material.
To build a strong squad you don't always need star players, but the players currently at Bayer Leverkusen have fairly even quality in each line so they can produce quite good performances from the start of the season.
That is true, they know what they are doing not just when they are playing, but from training to building a roster they are managed very well. It may sound a little funny, but it is the typical "German" way, they are doing their job very well, they do not showboat, they do not celebrate, they do not party, they do not just try to one up others on transfers with insane money to tell the world how great they are or anything, they just do business and they do it well.
I think that's important because we are talking about something that would benefit them a lot, look at Newcastle and Chelsea, they spent x100 more money and did a lot worse, that's important. Xabi of course played a big role as well, he has a great football mind and it shows.