It is, but it comes with the character. At least AC is a balanced enough game where you only have to deal with "can I execute?" when picking a character. Other more unbalanced games pretty much strike out certain cast choices, even if you love a character. (Marvel 2, for the easy example)
However, maybe I-no is a character that should be streamlined slightly (I personally dont know, never tried to do her hard stuff). At a certain point, common sense has to kick in and if a character is waaaay harder to use than the average, some tuning is in order.