Going from 2 wings to 3, I didn't need that much exp and such, however going from 3 to 4 has been a huuuuge haul. I'm at 4 days left before evaluation and nothing is making me go from "stay at rank" to "ranking up". I've probably done around 30-40k exp from campaign battles as well as a lot of various previously uncompleted higher ranked Campaign Ops (ie. Not streetsweeper 7 times in a row). I heard it gets hard to rank up the longer it takes but... why? That just seems retarded. I don't have the time to do a huge grind on one day, but rather I do little by little each day. Is there something else I'm missing?