Is it true that Imam Ahmad and Ibn Ma'in said that Al-Layth ibn Sa'd was the most accurate of those who narrated from Ibn Ajlan and Al-Maqburi, and that he took his narration from Ibn Ajlan before his memory deteriorated?

Al-Mizzi in "Tahdheeb al-Kamal" and Al-Dhahabi in "Siyar A'lam al-Nubala'" and "Al-Mizan" reported from Ahmad and Ibn Ma'in their authentication of Muhammad ibn 'Ajlan and their praise of him. As for the issue of Layth's narration being the soundest of narrations, no report from Ahmad and Ibn Ma'in concerning it has been found, and it is advised to further research in books of Rijal and biographies.