Despite how many percent the winning ratio for Manchester United against Bayern Munich is not important yet when another match result between Copenhagen vs Galatasaray have one match teams. Current performance from Bayern Munich keep in unbeaten record seems difficult for Manchester United and I think you give too much winning percentage for United who have bad performance after defeating by Newcastle United in domestic league.
Manchester United have fatal mistake on last match in Champion League, have leaded 3-1 over Galatasaray and have conceded two goals make this match have been draw and difficult position for last match not only must win from Bayern Munich but also United need draw result on other teams match between Copenhagen vs Galatasaray. I don't think Galatasaray or Copenhagen won't loss their opportunity qualifying to 16 round because one step closer their chance to get 16 round position without waiting the other team matches result.
Say Manchester United is able to win the match against Bayern Munich, but if the match between Copenhagen vs Galatasaray was successfully won by one of the two, Manchester United's victory was also in vain. Opportunities for Manchester United qualify for the next round when facing Galatasaray and if the match does not end in a draw then it is likely that they qualify for the next round. Pessimistic if you see the results for Manchester United because they have to fight to win the match and hope that the other two teams will draw in the last match.
Not to mention spoke with Bayern Munich who was in good condition so that facing them would be far more difficult. Erik Ten Hak did not give good results this season for Manchester United and it seemed he was under a great pressure following a fairly small opportunity in the Champions League and strangely he still entrusted players who made mistakes many times while playing.