Given his position as CEO, there aren't any employees he could "fraternize" with, if "fraternizing" implies no hierarchical reporting relationship. I think in

Given his position as CEO, there aren't any employees he could "fraternize" with, if "fraternizing" implies no hierarchical reporting relationship. I think in this context that is the significance of the word, which like "fraternal" is connected to the concept of brotherhood and connotes at least nominal equality between the participants.