I play Kano, and as I said many times I love his playstyle and aesthetics in MK11. He clicks with me more than any other character in any NRS game, including previous Kanos. I'll stick with him even if he were not buffed, even if he were nerfed, I don't f****g care. He needs some help, that's for sure, but I love the struggle and the feeling of playing differently than any other character. For me, his moveset is perfect, except for some framedata that needs some adjustements, and the gameplan, while risky, is hella fun.
I play Cassie too, and she's awesome. She's cool and she's super strong but not braindead, you are likely using all her tools in order to win a fight. However, still, if I had to chose between she and Kano, I'd keep Kano, regardless the difference in terms of tier placement.