Is it permissible to kill a man among the specified categories who possesses military counsel or opinion?

Primary text

It is permissible to kill a man from those mentioned who possesses opinion or counsel that assists in warfare. This is established because Durayd ibn al-Simmah was killed on the day of Hunayn while he was an old man incapable of fighting, yet he was taken out to lend counsel and seek good omens from him, and the Prophet (peace be upon him) did not object to his killing. Counsel is considered a great form of aid in warfare. Evidence supporting the weight of counsel is found in the statement attributed to Mu'awiyah, who said to Marwan and Al-Aswad that sending them with the counsel and stratagems of Qays ibn Sa'd against Ali would have been more grievous to him than an army of eight thousand fighters.