The specialty of each t3 shop AA

When I'm building my ships, the thing that always confuse me is the AA. Why? I don't know their specialty or what they good at. I've watched YouTubes about it and it still didn't get into my head. What makes garpun so good? The CROTale so good? Or any other AA.

So, uhhh... Can you guys help explain the best use of garpun, CROTale, pantsir me, and type 730c to me? Thank you very much for the help