Did a further test, and it really seems only the 1st season girl's gear which matters. I used the #weakinseason team and replaced only the 1st with my best geared girl, and now my defensive team is stronger than the offensive one and the very same as if I used my main team and just switched that girl to position 1: ... ehm wait, it was, but big surprise, now they are identical: This changed since some back and forth testing last night, so probably a fix arrived today?