You have a guy who is crippled by something that would genuinely be psychologically crippling, and then you take out the main part of it that makes it unique, namely that it was actual cowardice that would legitimately have him hate himself for years, in an easily grokkable and freshly impactful manner for the readers, and throw it away to make it him being just plain wise instead? It removes a huge chunk of complexity from his character and downgrades the ordeal he's been working to overcome to mostly an illusion of what we thought it was.
Fear of something (say, a knife) that has hurt you in the past has been done enough times, and Japanese protagonists misunderstanding or underestimating themselves is more than overdone. What a disappointment.