One gauge of how Germany might succeed or fail with the current influx of migrants is to look at the other large cohort of Near East Muslims who live in Germany: Turks. There are 2.2 million German residents of Turkish descent.
According to the latest analysis (g), only 14% of Germans of Turkish descent get an Abitur, the formal high school degree that is the most common gateway to a college education. The average for all Germans is 28.5%, the average for all 'persons with a migration background', i.e. non-ethnic Germans, is 30%. That number includes sub-groups who get an Abitur at extremely high rates, such as Spaniards (43%), Ukrainians (51%), French (62.4%) and Bulgarians (45.9%). 1/3 of Syrians and Afghans currently in Germany got an Abitur, but most of them arrived under very different circumstances than the ones coming now.
Many Turks have succeeded in Germany, an Abitur isn't the only way to success, etc., etc. But still, an Abitur is by far the most common way to gain a solid education and a stable middle-class existence. The fact that 3rd- or 4th-generation Turkish-Germans who have been born and raised here are dead last in the rankings, and that 86% of them don't get an Abitur, is not good news.
Perhaps instead of spending billions of euros to educate hundreds of thousands of new immigrants, it might be a wiser option to spend money improving the educational performance of 2.2 million citizens who are already here and struggling?