How are your defenders doing at that rank?
I've taken them off defense to farm expeditions for invis shrooms, i dont think they would do well with the current stuff i have against someone committed to getting in. They'd wreck people who go unprepared, but I'm completely changing around both the armor and weapons i want to use on them, so what i was using i stopped upgrading and the stuff i want to use I'm still upgrading - it's kind of all lower than i want it to be at this rank.