I'm not concerned about stepper to stepper matching, but amp volume to amp volume matching. Given the lack of fine granularity in level setting, I just can't imagine they're the same.
did you measure the output of each at the specified level to verify the levels match? Given the steppers, it seems really unlikely that they're exactly matched.
I like the way my tooleaudio modded 2900 sounds, but I've never heard the monarchy 18B. Where on the east coast are you, maybe I can get it to a meet you could make.