A second account of likeness asks whether one being can take the other's place or fulfill the same functions. On that criterion no creature can replace God, because created knowledge and power are limited and dependent, whereas divine perfections are not.
بحيث يسد أحدهما مسد الآخر، أي يصلح كل واحد منهما لما يصلح له الآخر
Such that either can stand in the other's place or do what the other can do.
Two teachers may substitute for each other in a bounded classroom role. That does not make either a substitute for the Necessary Existent. Equality in a restricted function differs from equality in independent divine perfection.