Everyone one of the SHs have seen tragedy as kids, they developed character growth, issue is Momo all he does is cry at any given moment. He has cried and acted cowardly so many times I have lost count.
The one thing WCI did for me is confirm how much of a badass Sanji was a child, he showed courage as a kid and wanted to get away from his family and find a new life... that's character growth, and starved for days with Zeff as a kid, didnt see him crying there