Is it recommended for the Imam to appoint a deputy to lead prayer for the weak congregation members?

Primary text

It is recommended that the Imam, upon departing, appoint a successor to lead the prayer for the weak members of the congregation in the mosque. Ali, may Allah be pleased with him, acted upon this precedent. When asked to appoint someone to lead the weak, he stated that if he appointed a man, he would instruct him to lead them in four rak'ahs. It is also narrated that Ali appointed Abu Mas'ud, who then led the people in prayer in the mosque.