Cassie was strong, but not broken strong, unlike Kang is.
And nqh Cassie aint perfect, she is perfect s** now. Almost no one use her, and she is 100% s*** at Pro level. Her placing was thanks to SonicFox. No one except him has decent result with her. After he dropped her, she is barely used.
Cassie has 1 good KB, that was a solo move, Kang has 6, 4 of which are high damage landing on will every single set. Cassie has s**** FB, Kang has one of the best.
Kang has better zoning and anti-zoning than her. Also he is better at stealing turn and in pressure.