This reminds me of Avatar when Aang the air bender is the only person who can beat Toph the earth bender in the ring. Because his style is completely about avoidance and he spends so much time off the ground, Toph can't even tell where he is half the time. Though later when she teaches him earth bending we can also see this as a weakness, that earth bending is about standing your ground, and that's the opposite of air bending, which is going around something.
Might be a random tangent, but just backing you up on how this makes the most sense. If you know how Cass reads her opponents so well, you need to take that information away.