What happens with transfers in a player's career?

I started my new career this year for Bayern and by my third season there is not a single profiled central or defensive midfielder on my team, with central defenders rated 67 and 71 playing in the middle of the pitch.

I couldn't finish my career for Stuttgart, first there was a bug with contract renewal, then the team sold the best players every year (even after winning the league and cup) until almost all players rated 70-75 were in the starting lineup. I figured it was because of the team's goals. After that I started two careers for Bayern and in each of them, my team sold central midfielders and wingers and bought attacking midfielders.

It's been a problem in previous installments of the game, but this year it just makes the careers unplayable. What can fix this problem? A change of tactics for my Team before? A change of scheme?