“How can we best get by that initial German-No response?”
First, never assume that the German-No is hard and fast. Often it is simply their immediate response to a question which has been stated to them requiring yes or no. In other words, they feel that they have to make an immediate decision.
Just as an American-Yes can range from 98% to 68% to 38% to 18% in terms of level of commitment, so can a German-No be anywhere in that range.
Second, in order to get an initial sense for roughly where the German-No is in the commitment range ask in a friendly and polite way:
“Why not?” or “Ok, but can you, please, tell me what the barriers are to you giving me a yes?” or “Ok, I understand. Well, what can I do in order to make it easy for you to say yes?”
Third, take whatever responses you get – the reasons for the no – and work on each one individually. Think of what it is like to whittle down a stick with a penknife, stroke for stroke, cut for cut, shaving for shaving. In other words, overcome each no-reason, one after the other, patiently, but persistently.