I read the LN. While Jeanne does say Souma is emotional and Maria rational, she seems to be talking about the fact that Souma isn't bound by their world's common sense and traditions, unlike Maria. How she came from that to emotional vs rational, I don't know, except maybe that she couldn't see the rationale behind Souma's actions, so she concluded it didn't exist. (Which seems weird, because she knows that unconventional or not, it did work.)