All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger.
The Imaamah (leading people in the prayer) of the person whom you mentioned in the question is correct and acceptable provided he recites the Quran properly and does not deliberately make mistakes in the way he pronounces the words, and provided he does not make pronunciation mistakes in Al-Faatihah (the opening chapter of the Quran) which change the meaning – as it might be understood from the question. The fact that he is too forgetful when reciting does not invalidate his recitation and his leading of the prayer. When the Hanafi Scholars mentioned the people who are disliked to lead the prayer, they did not include a person who is too forgetful or whose memorization of the Quran is not strong. However, the jurists stated that it is disliked for a person who makes too many pronunciation mistakes –which do not change the meaning- to lead the prayer. Undoubtedly, it is better to appoint a person to lead the prayer who recites well and does not make pronunciation mistakes.
On the other hand, it is permissible for one person or more to hold the Mus-haf (i.e. the Arabic Text Book of the Quran) while being led in the prayer for the purpose of correcting the Ihraam in case he forgets. If one person fulfils the task of correcting the Imaam, then there is no need to appoint other people to do this task. For more benefit please refer to Fatwa 83531.
Allaah Knows best.