SOPP630: If in a church there is a need for an organist, and the only two keyboardists are a professional concert pianist and a mediocre/intermediate organist, who would be better to play the organ?

This question was sent by Andrei, and he writes:

“Hi Vidas and Ausra!

I have a question for you:

If in a church there is a need for an organist, and the only two keyboardists are a professional concert pianist and a mediocre/intermediate organist, who do you think would be better to play on the organ?”