Factual error: Aside from the fact that split-level entries didn't exist in 17th century Austrian palaces, there would be no windows in main state rooms if you did enter the front door and step down.
Continuity mistake: When the captain sings for the first time and hugs the children, Gretl is under his left arm. In the next shot, he raises his arm and she is nowhere to be seen. Then, when Maria motions for Gretl to give the Baroness the edelweiss, she is back under his arm.
Answer: True, but a decorated and highly respected command officer, particularly one with proven wartime experience, is still a major asset. While he might not be directly familiar with the current equipment, naval tactics wouldn't have altered to any great degree and his ability to lead and inspire those under his command would remain the same.
Tailkinker ★