Hey, don't worry, your husband will have a VISA attached with his passport. There are two things you will get back with his passport, one is the COPR, one is the immigration VISA, categorized as FM Class 1. So, if you book his travel smartly, he doesn't need to have another VISA from Germany. The best way is to contact a travel agent either in Canada or in Turkey and explain your situation to them, they will help you on that.
And majority International Airlines won't require you to pickup luggage during flight transit, and most time those international connecting flights are in the same terminal, which it doesn't require you to go out and go through another security check.