Bayern Munich full strength football team could not win the match against FSV Mainz 05 full strength football team because they did blunders in this match and match was ended with the result of 2-1 and Bayern Munich lost this the match but after this match that team did good come back against RB Leipzig full strength team and won the match one sided.Bayern Munich did 5 goals in this match which is Osum performance by the players of that team. Leverkusen full strength team will play next match against Borussia Dortmund full strength team and Borussia Dortmund is favorite for that match because head to head performance of Borussia Dortmund is Osum and that team won for more times and Leverkusen won for only one time but It doesn't mean Leverkusen could not win against Borussia Dortmund and match will be tough for both teams and any team could be winner of this match.
There have not been any strategy shortages or anything that you are talking about. Did you check the table and see where Mainz now is? I think it falls short of recognizing that Mainz has founds its way to the top and made sure that they are now perceived as a team that can beat Bayern Munich. They won't like it but who cares?