According to one theory, the Bavarians are not one of the old tribes like the Alamans, Saxons, or Langobards; but a combination of Alamans with the native Celto-Roman (and partially Slavonic) population.
So if this theory is true, we can expand the Alamans in a subtle way: Let them settle Bavaria more slowly, but still numerously. Then a Bavarian identity can perhaps be prevented; but the Alamans will still supersede the cultural identity of the resident population.