Ah, okay, for anyone else stuck: you have to go all in on magic or weapons. I had a single choice in weapons and the rest magic and that meant I couldnt hit the stat checks.
Viewing post in Full Release + DLC announcement (new MC/ROs) comments
Yup, same exact mistake. I was a bit surprised about how stringent that stat check was (the one before that, at least, I could accept as a skill issue on my part). At least re-loading isn’t too hard though.