But who said that exactly?
If Yetos is correct, afaiu, the Hellenes were a non-Mycenaean group speaking a 'NW Greek' dialect which expanded south. Similar views are based on things Aristotle said among others, about a tribe of Hellenes formerly called Graecoi in Epirus, about 'ancient Hellas' in Epirus etc.
If I am correct (I follow Herodotus) the original Hellenes associated with the Dorians originated in Phthiotis, expanded first to NW Greece where they were called 'ethnos Makednon' and then expanded south. If that is true they were 'Mycenaean' related but had expanded to Epirus/West Macedonia before the movement south.
Unfortunately I don't remember exactly who said what and the posts have been deleted, but someone said it, someone even had a map, I remember Yetos had another map claiming to represent the proto-Greek area, then Angela cited the Encyclopedia Britannica, which stated that Epirus was settled by Greek-speakers associated with Myceneans since the Neolithic. I suspected this was wrong and after learning some things here I am convinced it is.
As long as there is a consensus on the continuity of Mycenean and Homeric Greek I will accept it since I am not a linguist to interpret Linear B on my own. As for the Hellenes, as they were probably only one of several Greek-speaking groups they might have been central to the Greeks gaining consciousness about being one people, but I am more interested in the origins of Greek speakers in general. Were the Myceneans the first ones to arrive to the region? Were they the only ones? Were they even linguistically homogenous? I would like to know these answers.