This is taking me back to my early days of taping. The following is really bad advice, but I made some intersting recordings with it:
I had a pair of Core-Sound LCB's, a pair of LCSC's, a SP-Preamp and a legacy Sony Mini-Disc Recorder. This is a very similar setup to your church rig. i too wanted to run all 4 of my mics. I used a headphone splitter out of the SP-preamp and ran both sets of mics. It worked, but I am sure someone here could explain all the electrical, phase and impedance problems better than me.....
Have fun and experiment!