I'm sure he would pick up on some things, but he would also be heavily influenced by much later forms of Greek, where means would have changed. I have spoken to Greeks about ancient texts and their reactions vary — some indicated they could understand a lot and some very little. A bit like a modern English speaker approaching Chaucer — I can understand a fair bit and am helped by my knowledge of Broad Scots but other people complain it is barely intelligible to them. (There are people who complain the same about Shakespeare and even Dickens.)