by what see at Hellenistic times and text
ancient Greeks and even Homer had r as a vowell
the 3 in Hellenistic according the Alexandreian forms and inspirations were ρ 'ρ ρρ (r hr r'r)
Iapetoc comparing the German Language and words like warrum etc suggested might be from Thracian origin
the forms ρρ and 'ρ are pronounced but not marked in modern Greek, the turn is about 400 AD
I still do not understand which is the gutullar and which is the uvular among the 3 r 'r rr
the rr is like r'r for those who know like word αρρωρηξ
as an example something to find easy Acts 18
1 [a]Μετὰ ταῦτα
[b]χωρισθεὶς ἐκ τῶν Ἀθηνῶν ἦλθεν εἰς Κόρινθον.
2 καὶ εὑρών τινα Ἰουδαῖον ὀνόματι Ἀκύλαν, Ποντικὸν τῷ γένει, προσφάτως ἐληλυθότα ἀπὸ τῆς Ἰταλίας καὶ Πρίσκιλλαν γυναῖκα αὐτοῦ διὰ τὸ
[c]διατεταχέναι Κλαύδιον χωρίζεσθαι πάντας τοὺς Ἰουδαίους
[d]ἀπὸ τῆς
Ῥώμης, προσῆλθεν αὐτοῖς,
3 καὶ διὰ τὸ ὁμότεχνον εἶναι ἔμενεν παρ’ αὐτοῖς καὶ
[e]ἠργάζετο, ἦσαν γὰρ σκηνοποιοὶ
[f]τῇ τέχνῃ.
4 διελέγετο δὲ ἐν τῇ συναγωγῇ κατὰ πᾶν σάββατον, ἔπειθέν τε Ἰουδαίους καὶ Ἕλληνας.
acts 9
10 Ἦν δέ τις μαθητὴς ἐν Δαμασκῷ ὀνόματι Ἁνανίας, καὶ εἶπεν πρὸς αὐτὸν
[h]ἐν ὁράματι ὁ κύριος· Ἁνανία. ὁ δὲ εἶπεν· Ἰδοὺ ἐγώ, κύριε.
11 ὁ δὲ κύριος πρὸς αὐτόν·
[i]Ἀναστὰς πορεύθητι ἐπὶ τὴν
ῥύμην τὴν καλουμένην Εὐθεῖαν καὶ ζήτησον ἐν οἰκίᾳ Ἰούδα Σαῦλον ὀνόματι Ταρσέα, ἰδοὺ γὰρ προσεύχεται
as you see r in Alexandreian psilosophers was vowel taking aspirations