What is the ruling on the Imamate of one who cannot articulate certain letters, such as 'Dhad' or 'Qaf'?

Primary text

Regarding one who cannot articulate certain letters, like 'Dhad' or 'Qaf,' Al-Qadi states that his Imamate is disliked but valid, whether he is a non-Arab (*A'jami*) or an Arab. For one who recited '{Wa la d-dallin}' [Al-Fatiha: 7] with a 'Zhaa' sound instead of 'Dhad,' his prayer is not valid because it changes the meaning, bringing him under the ruling of the one with a lisp. The Imamate of one who stutters ('Tamtaam'—repeating 'Taa') or one who repeats 'Faa' ('Faafa'') is disliked, but the prayer behind them is valid because they articulate the letters completely and the repetition is an involuntary excess for which they are excused. Their promotion to Imam is disliked due to this excess.