All perfect praise be to Allah, the Lord of the worlds. I testify that there is none worthy of worship except Allah and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and Messenger.
There is a difference of opinion among the scholars regarding the issue of the obliged being led by the volunteer; and there is no doubt that the view of those who accept its validity is preponderant. Accordingly, if the obliged and the volunteer are equal in the various attributes of an Imam, or if the obliged has more such attributes, then there is no doubt that he is better suited, in this case, to lead the prayer. This is because the greater abundance of these conditions makes him better suited according to the Hadeeth, and if they were equal then his leading the prayer escapes the disagreement.
When the obliged has less traits of leadership than the volunteer, then there is no harm in him being led. Some of the Shaafi‘i scholars followed the opinion that it is best for him to pray by himself (individually, not in congregation) in order to avoid the disagreement.
Allah knows best.