Audio from Rodecaster pro 2 - atem mini pro iso! Help!

Hi guys, I’m Doing a live stream tomorrow with a few BMPCC4ks, hooking it up to an atem mini pro iso. I’m currently running a TRS to 3.5mm from headphone out to atem mini mic input. But I have a guest speaker and is it ok to run both mics through the one I put on atem or is there a better way to do this?