Just because a general has gotten his position from family connections doesn't meant that they are inherently incompetent (whatever that means). For example, the Parthian general Surena was chosen to escort Crassus because of his family's prestige (well that, and the fact that he had a personal army).

Sorry, we don't allow throughout history questions. These tend to produce threads which are collections of trivia, not the in-depth discussions about a particular topic we're looking for. If you have a specific question about a historical event or period or person, please feel free to re-compose your question and submit it again. Alternatively, questions of this type can be directed to more appropriate subreddits, such as /r/history or /r/askhistory.