I've made the presumption that there is only ever one active shooter at a time. Introducing multiple shooters would substantially increase the difficulty.
The mics that you've referenced (goodness me those are expensive things!*) have, as far as I can tell from the manufacturer's deeply unhelpful website, a simple 2 pin connection. That being the case you should be able to use something similar to the 'Keyes Microphone Sound Detection Sensor' board. This comes with a 2 pin microphone soldered to the board. Desolder this and replace it with the lead to your microphone, or a suitable socket that you can plug the mic into. Repeat with all 5 mics.
The digital output level for the sensor is 5V. This is too high for the Pi's 3.3V GPIO pins, and may cause a magic smoke release. You can use something like the Adafruit 8-channel Bi-directional Logic Level Converter to convert the 5V output down to a safe 3.3V.
Connect each D0 output pin on the sensor board to a 5V pin on the logic level converter. Connect each corresponding 3.3V pin to a Pi GPIO pin.
You adjust the sensitivity threshold of the audio sensor boards using a small screw on the top. When the audio level at a microphone crosses this threshold, the output from the corresponding sensor board is driven high (5V). The logic level converter converts this to 3.3V and outputs it to a GPIO pin. Use Python to create some kind of association between stands and pins. If stand [x] is in use, listen to GPIO pin [x]. When it goes high you stop listening to the pin, fire your clay, wait for a second or two till the racket dies away, then start listening to the pin again for the next 'PULL'.
*Gadzooks those are expensive microphones. If it were me, I'd experiment with something like these EKULIT EMY-6027P/N-R-42 IP67 rated cheap things, possibly in a plastic cone to reduce off-axis audio from leaking in.