The real question is whether E-V13 was present, and to which extent, in Pre-Roman Greece. It is for sure in the Thracian parts of the country and due to some Thracians trickling in, but not for the wider Greek region and earlier periods of the Late Bronze to Early Iron Age. Also, its possible that local Greco-Thracian E-V13 lineages, just like other classical era Greek lineages, largely died out and being later largely replaced by E-V13 from other sources (like other Roman provinces and Vlach-Albanian migrations). Therefore even if E-V13 was present earlier, it doesn't prove the continuity to the modern E-V13 branches in Greeks, unless we find the same subclades.I didn't say anything about purity, just relative continuity in central and southern Greece from the LBA to IA, which is a fact. You probably thought I was arguing for continuity between BA Greece to modern Greece, try reading more carefully next time.
Not sure what you mean with "absurd haplogroupic situation" in modern Greece, modern Greeks are descended from the Eastern Roman Greek-speaking population (Romioi) and neighbouring Balkanic ethnic groups, nothing really surprising if you look at history and geography.
E-V13 in Greece is not exclusively Albanian, part of it comes from the Roman Greek population of Imperial period and Late Antiquity.