Posting today what looks like a really useful seminar from Bob Kauflin at Sovereign Grace, on effective piano playing in a worship band/music team. This is the third part of the seminar which deals with lots of things about chord colouring (with add 2, add 4), inversions, intros and leaving space for your band. Sometimes classically trained pianists find it hard to transition to playing with a band. This may be what you are looking for! I must admit I also share his enthusiasm for the add2 and the open 5th. Perhaps this would be worth a look together with all your pianists! (By the way, if there is a specific topic you want to learn something about Bob K has kindly indexed the video beneath).
http://www.worshipmatters.com/2012/01/07/the-piano-in-contemporary-worship-part-3/
You may also enjoy:
The Blessings of multi-generational music teams Music ministry training paper