Zidane would not come into a less competitive club with no discipline and solid attitude. He's intending to be the mentor for France national team.
I don't think Zidane only wants to manage a solid and competitive team. Remember when Zidane managed Real Madrid for the first time, that club was in a bad situation. And after he managed it, then Real Madrid became a solid team and they got some trophies, including UCL trophy. It indicates Zidane won't manage an established team only.
Zidane is a talented, and surely won't take the risk.
If he thinks he is talented enough, he must be brave to take risks.
Anyway, I don't think Zidane is a person like you think. I have explained above, that he wanted to take a risk when he managed Real Madrid. It was his debut as a professional coach for the main squad of one of the biggest clubs in the world. It was very risky, the opponent was Barcelona. But he successfully got great achievements there.