As I commented in https://www.quora.com/Why-isnt-G…
FWIW, if you look in terms of common stems (someone actually went through Pokorny’s etymological dictionary and did the stem counts: The Distribution of Indo-European Root Morphemes ), Armenian has the most common stems with Greek. Given that Phrygian was next door to Greek and no other languages from close by have survived, that makes sense.
Yes, lexicostatistics is no substitute for the comparative method. It’s not nothing either.