Is it relevant that third-party recruiting firm fee's are typically 20%, upwards of 30% for "top talent" of the negotiated base salary? 25% is a norm or more "h

Is it relevant that third-party recruiting firm fee's are typically 20%, upwards of 30% for "top talent" of the negotiated base salary? 25% is a norm or more "hard science" mechanical / engineering (non CS), while 30% is more of a norm towards confidential financial firms.