The Germans prefer consulting over serving. To consult the customer is to work auf Augenhöhe, at eye-level. The German people instinctively reject any form of master-slave business relationship.
And the German customer prefers a supplier, consultant, vendor who insists on a business relationship auf Augenhöhe. Germans don’t want to be served, they want to be consulted, by an expert, at eye-level.
Collaboration in the American business context is defined first und foremostly by the customer. Customers not only define what they want, but also to a significant extent how they want it.
Collaboration can mean a high level of client input on the how. Customer requests are understood by both parties not so much as open topics to be discussed by equal parters, but as orders formulated and issued by the customer.