I don't think he wants to become stronger only for himself. Yes, as a child he wants to become a "real" man, someone who can survive for himself and protect his family... But while reading I have the feeling that he's also worried about being worth for his wife, and he also wants her to see him as a man and be attracted to him. Because he's younger than her and she's a pretty talented and strong woman who is a great hunter... He wants to be his equal, be as capable as his wife.
Bro, I don't care what anyone else says (too much). You are right, that is exactly how i feel when men pull this, 90% of the time they just want to feel better about themselves and only 10% of it is for the girl whenever they put distance between them in the name of their relationship. But I am trying hard to focus on the fact that he is a child who just wants to grow up fast in a world of adults.
He isn´t doing it for her, he is doing it for himself...
It isn´t a bad thing, but he doesn´t have to lie at least.