As far as I can tell, Fingerpick doesn't use wav loops. It's got samples of a real acoustic, with some MIDI loops for the different finger picking styles.
You play a chord, and it picks to a preset "style". The key thing is, that the MIDI loop changes to reflect the chord shape to make it more realistic - so it's not just a transposed loop.
TBH, it's not my favourite plugin. I find UJAM Virtual Guitarist & NI Strummed Acoustic far better for the guitar sound, but they're mainly suited to strumming chords. UJAM VG Silk does do finger picking, but it's on a nylon guitar. VG Amber (the acoustic one) only does strummed chords. I got fingerpick because it does finger picking on a steel strung acoustic.
Most of the time I only use these sorts of plugins for getting ideas down. I'll normally re-record with a real guitar when I get the chance, but if the VSTi ends up sounding better I may keep it.