Mr. Brumby testing a doubling effect ?
In a 'PA' public address system application, if you can't get awesome gain before feedback with one well selected microphone (and an identical backup/s next to it), with some manual fader riding and compressor limiter and equaliser to keep unforeseen nasties in check,
then it's job you shouldn't be attempting
unless suckered to do it for free sex or roadietard prestige If ratass rude reporters and snobby TV crews with pushy bossy boots no life producers want a free ride off your multi channel isolated distribution amp after all the work setting it up (and cash blown to buy it),
then they can PAY for a balanced line (aka HIRE/RENT fee etc)
or run around themselves and setup and use their own mics
or use The Force Summing/mixing together the 7 microphones above makes for a sharks teeth comb filter akin to 'a day at the races in the bush' sound quality
Good luck trying to set up gating or delay parameters for a 7 mic setup
especially dealing with a quiet or non consistent speaker