And to the person who asked the main question.. Muawiyah raa didnt "attack" rather fitnah makers killed people from both sides to start a fitnah. And later on the two sides agreed to peace and the judgement of the book of Allah. Also, know that history books, such as Tareekh Al Tabari, mention hadeeths with their chains, saying in the intro that it is up to the reader to look into authenticity. So not everything there is authentic, theres so many weak and fabricated narrations, and many narrations regarding this topic have the shia Abi Mukhnaf in the chain, a known liar, who they rely on very much.