how big are the venues your talking about?
the only time Ive run multiple mics in a room that have produced a good tape when mixed have been either a onstage+foh pull or this 1 time in Baltimore at really TINY club called 13th Floor and the band didnt use the p/a for anything but vocals. we set up 4 mics about 10' from stage all on the same stand, 2x MG m200 + 2x AKG 391, AKG's in x/y and MG's in ortf.
setup similar to a " W " shape
...mixed the 4 channels in DP3 to give it a nice wide soundstage(no hole-in-middle due to x/y) and everything is crystal clear.
let me see if I can find a track to put up for you to hear.
guess the story comes down(imo) to 4 mics being used only in damn small places or spread out(onstage and at foh-or center). you'll have to be careful in mix-down to avoid phasing issues and delays.
anyone else want to chime in?