The secret to emulating ANY instrument with sampled synths is in the articulations and the details.... basically, you need to be able to get inside the head of how a real player of that instrument would play it, then, be able to translate that to midi.
Lacking that, the best samples will sound fake.
On the other hand, using a halfway decent sample or midi patch, (TTS or GPO) put the details where they should be and you will have a very convincing track.