I cannot see any way in Audacity of setting it for 4 mono channel recordings??
Audacity will only record from one “thing” or device. Sometimes, if you have a well-behaved, multi-channel mixer or interface, you can coerce Audacity into recording more than stereo, but that’s not always possible.
You can get four independent channels with perfect reliability by using two stereo recorders. Each recorder has its Left and Right split so Left is one performance and Right is the other.
One of the recorders exports its stereo show as perfect quality WAV to the other for editing. The only technical problem with this is the possibility of the two sampling rates not matching. Match up the first words or sounds and roll to the end of the show and sort how far off they are. Effect > Change Speed to one of them. You only have to find the offset time once unless you change either recorder.
Koz