2. How did Siegfried’s statement that he was a vassal to Gunther, increase Gunther’s worth in the eyes of Brunhild?

Brunhild agreed only to marry a man who was equal to her physically. Siegfried, claiming to be Gunther's vassal, gave him believablity and also won the athletic contests for him by using the cloak of invisibility.

Wow, this was a great epic...... I haven't read it in years, but I'm going to look it up right now and do that.