I think Lomachenko's age is the key. His prime skills are certainly good enough to beat Haney despite The Dream's size advantage. In his last few fights Loma has not looked like the Matrix of old. This is not to say he's looked bad but the standard he set for himself was very high. He has been very good, not great and I don't think very good will be able to offset the combination of Haney's skill and size.
Ok but which one is more important to the outcome of the fight in your opinion out of those two factors?
His age. He will need to close the last few rounds in top form. Not sure if he can do it at 35 though.