I think that's a healthy attitude toward modeling.
Models are approximations.
I sincerely hope that's not the case. I am particularly eager to do this with respect to voice, where I think the traditional conceptions are neither quite valid nor quite intelligible. But after a semester's work last spring endeavoring to draw such distinctions in a comparative grammar class, I don't think this is a very easy thing to do. I am certainly not a defender of tradition at any cost, but I cannot imagine a new systematic grammar that will not owe a prfound and solid debt to the work of more than twenty centuries of previous effort expended on understanding the way the Greek language works.