Aeolism: Latin as a Dialect of Greek/Aeolism: Latin as a Dialect of Greek is a paper on that. And Are there any accounts of the Romans realizing linguistic similarity between Latin and Germanic languages? • /r/AskHistorians is a Reddit thread of it.
The locus classicus is Dionysius of Halicarnassus, but the idea was doing the rounds:
The language spoken by the Romans is neither utterly barbarous nor absolutely Greek, but a mixture, as it were, of both, the greater part of which is Aeolic; and the only disadvantage they have experienced from their intermingling with these various nations is that they do not pronounce all their sounds properly.
, Linguistics PhD candidate at Edinburgh. Has lived in USA, Sweden, Italy, UK.