With around 35,000 US soldiers stationed in Germany, most of them enlisted ranks for whom property is generally not an option anyway, the likelihood that anyone here can speak from personal experience about how something like this works is low. Everything else is like looking into a crystal ball with the bearded lady at the fair...
You are already on the right track with a consultant who has experience with this kind of thing, aren't you? What is stopping you from just taking all the documents and walking into a bank?
You will have to judge the rest yourselves anyway. I have no idea how reliable a statement is in the US Army that you can stay exactly at that location in Germany. Because basically, your husband as an active soldier can be withdrawn and sent somewhere at any time where the US presence needs to be increased. If the USA relocates its presence in Europe or reduces it in Germany, he can be recalled to the USA... or he could be transferred to Poland. Can this really be ruled out?
And the service time will end at some point. What then? The house will probably have to be paid off over 25 or 30 years.