Bayer Leverkusen management team has everything it takes to fix things up with their team before the beginning of next season and still remain relevant in their league. Xavi Alonso departure shouldn't be a reason for the club not to move forward, and besides no good coach or player will last forever, so it's for the team to make a good replacement signings as regards to coach which they lost the hands of Real Madrid.
They might have everything as you say to fix things up with the team but it will still not be up to the standards of Bayern Munich and that's the more reason Bayern Munich will keep on been on top of the rest. Alonso's departure and some of the first team players leaving will definitely affect the team and don't forget that it was this sets of players and Alonso that gave Bayern Leverkusen it's first league trophy. So it's really going to affect them, the next coach really has a lot of work in his hands because Alonso has set the bar high for anyone that's going to take his place.