I just had a armor that was in shop that was already combined with those 2 armor kits/jacket. I was suprised because I thought you had to combine them first.
For some reason whenever I try to play rats I get 2 or 3 and then I can't find any more and get absolutely destroyed. Also whenever I went against rats with my Chana build I absolutely obliterated then. If I remember correctly I haven't lost against rats once.