How could Zayd ibn Aslam have been a mawla to Omar ibn al-Khattab, may Allah be pleased with him, given the significant time difference between their deaths, and is there a connection to Zayd's father (Aslam) having been a mawla to Omar?

Umar ibn al-Khattab bought "Aslam" in Mecca during the caliphate of Abu Bakr. Narrations differ concerning Aslam's lineage. Aslam accompanied Umar, memorized from him, and narrated from him, as well as from Abu Bakr and Uthman. Al-Dhahabi described him as an "eminent jurist." He is one of the narrators in the Six Books of Hadith. He died in 80 AH. As for his son, "Zayd ibn Aslam," he was among the imams of knowledge and hadith. Al-Dhahabi described him as "the exemplary, authoritative, leading jurist." He had sons who were narrators of hadith and exegesis. Zayd died in 136 AH and did not live during the time of Umar ibn al-Khattab. It is permissible to describe him and his sons as clients (mawali) of Umar because his father was Umar's client. Zayd had a study circle in the Mosque of the Messenger of Allah, peace and blessings be upon him, and his majlis included jurists and scholars. Malik described him as someone who would narrate on his own accord, and no one dared to challenge him.