it's definitely a tough balancing act - if you're too sure, you might miss signals that you need to adjust or pivot - you have to calibrate your own feelings and thought processes so that you are confident enough to push but also realistic enough to make good decisions.
or maybe you just bring a pusher onto the team to spread the word if the hacker is more of a diffident type
Confidence and being self aware doesn't have to be mutually exclusive. In fact, I believe they're complementary. Now, if you were to describe it as arrogance, then it may be cause to miss some cues.
or maybe you just bring a pusher onto the team to spread the word if the hacker is more of a diffident type