Jamieson, Fausset and Brown on Jeremiah 52:28

28. seventh year--in 2Ki 24:12, 14, 16, it is said "the eighth year" of Nebuchadnezzar. No doubt it was in part about the end of the seventh year, in part about the beginning of the eighth. Also in 2Ki 24:1-20, ten thousand (Jr 52:14), and seven thousand men of might, and a thousand craftsmen (Jr 52:16), are said to have been carried away, But here three thousand twenty-three. Probably the latter three thousand twenty-three were of the tribe of Judah, the remaining seven thousand out of the ten thousand were of the other tribes, out of which many Israelites still had been left in the land. The thousand "craftsmen" were exclusive of the ten thousand, as appears, by comparing 2Ki 24:14 with Jr 52:16. Probably the three thousand twenty-three of Judah were first removed in the end of "the seventh year"; the seven thousand and a thousand craftsmen in the "eighth year." This was at the first captivity under Jehoiachin.