I've always wondered, why is Kasumi's loyalty mission the only one where there's no third squadmate? I'm not sure if BW has ever given a reason but I'm curious.
I personally feel like Samara and Thane's loyalty missions didn't need a third squadmate, mostly because whoever you bring along during those missions don't do anything except appear in cutscenes. (At least that's all they do in my playthroughs).
I'd appreciate any info anyone knows. Thanks in advance.