By logic the standard assumption ought to be that there are missing centuries and the time is counted too short. I suspect that to be the case with culturally Roman-Christian Jordanes chronology of Goths, that it originally started from the same 4.2 kiloyear event as OL does (forum post). Furthermore, we now know with certainty this happened with Norse-Christian (read: culturally Roman-Christian) Norse saga compilers, whose compilations strech from Adam to Viking age kings with an erroneous tally count:
By comparing that above version list with the 4.2 kiloyear to 1800 BC predecessor lists (Weld-Blundell prism) in Sumerian King List, Oera Linda book, or even the Biblical lists putting the same names in c. 2000 BC time frame, we can see that the Norse-Christian list skips over vast millenias. Resulting in erroneusly short reading when counting generations backwards from medieval rulers (forum post, second post).Now we shall speak of how Norway was founded in the beginning, how the line of kings began there or in other lands, and why they are called Skjoldungs, Budlungs, Bragnings, Odlings, Volsungs or Niflungs, from which the lines of kings come. There was a man named Fornjot ['ancient-giant' i.e. Iku-Turilas]. [...] The king was called Burri [later in same text: Burri, who we call Finn] who ruled over Turkey [Tyrklandi i.e. Byzant, perhaps originally corruption of Turku, Finland or Turci; or Toroni, Greece or THÍR.HIS.BURCH of Tunis story]. His son was Burr, who was the father of Odin, King of the Gods [Ásakonungs, ...]Adam was the first man that God made. Seth was his son, and his son Enos, and his son Kaynan, and his son Malaleel, his son Phareth, his son Enoch, his son Mathusela the Old, his son Lamech [list continues to Noah, Saturnus, Jupiter, Persian Darius, Trojans etc ...]This count was one less than seventeen on both tallies. He was king when the [this compilation] book was written. They proceeded from the birth of our Lord Jesus Christ, mccclxxx and vij years [AD 1387] (source: Frá Fornjóti)