You can sim if the spice models are complete enough to include
design non linearities. Generally for that level design you contact
the manufacturer and ask that question about model suitability.
Note many manufacturers limit completeness of spice models to
protect IP. So tread carefully.
Measurement is, in the end if done properly, the best method. Thats
how many analog parameters are determined for datasheets. Over
several process runs and devices from each run. Its called, in the business,
process characterization of the part.
Regards, Dana.