We should probably start with the fact that the SA1530z User Manual states "The cabinet has no rigging points and is not suitable for flying." So while not flying it by the handles is good, that box is not intended to be flown at all. According to the User Manual it is also not intended to be pole mounted. The only recommended mounting option for the SA1530z is floor standing.
The 90x40 coverage of the SA1530z is a nominal value and applies only from 2,000Hz to 10,000Hz, at lower frequencies including those still well within the speech range the coverage may be much wider. So with that in mind, what does trying to cover the area in front of the stage do in terms of gain before feedback on stage, much less for if you have the sermon being given from the very area you are trying to cover at other times? Other than the keys, would people right in front of the stage get sufficient sound direct from the instruments and vocalists without needing additional reinforcement? And is there some reason you couldn't continue to use front fills?
Do you run the system mono or stereo? Is it used just for music or also for speech? Your proposed layout looks like you might end up with significantly varying coverage over the seating area from each speaker, and thus a varying stereo image, and at the same time might have poor localization and intelligibility for someone on the center of the stage talking.