If you have an average (not top grade) pianist in your band what do you expect from him/her.
Is it to carry the melody for the benefit of the congregation who may not know the tune or is to to provide a depth of harmony that may not be provided by the other available musicians.
My pianist is moving home and we have a shortage of skilled pianists able to play with a rhythm band and I am trying to select a replacement from those who can play the music exactly as written and those who follow the chords. My current pianist provides lyrical intros that guide the congregation directly into the song and will then (without completely ignoring the melody) provide some depth to the overall sound.
I have started receiving advice (not all invited)

about the replacement.