Greece has objected because they can; they have a veto on new EU members and have made this a red line. Other EU countries technically can tell Greece to accept

Greece has objected because they can; they have a veto on new EU members and have made this a red line. Other EU countries technically can tell Greece to accept Macedonia as it is (was) or no aid etc, but that's an extreme. Considering that "Macedonia" extends also into Greece it's not unreasonable to differentiate, into Northern and the other part. Without wanting to start a war, today's "Macedonians" are mostly slavs, and Albanians make about 25-30%.