Was Josephus Divided over Post-Flood Patriarchs?

Citing two passages of Josephus' Antiquities, Book I:

3:4. For indeed Seth was born when Adam was in his two hundred and thirtieth year, who lived :nine hundred and thirty years. Seth begat Enos in his two hundred and fifth year; who, when he had lived nine hundred and twelve years, delivered the government to Cainan his son, whom he had in his hundred and ninetieth year. He lived nine hundred and five years. Cainan, when he had lived nine hundred and ten years, had his son Malaleel, who was born in his hundred and seventieth year. This Malaleel, having lived eight hundred and ninety-five years, died, leaving his son Jared, whom he begat when he was in his hundred and sixty-fifth year. He lived nine hundred and sixty-two years; and then his son Enoch succeeded him, who was born when his father was one hundred and sixty-two years old. Now he, when he had lived three hundred and sixty-five years, departed and went to God; whence it is that they have not written down his death. Now Mathusela, the son of Enoch, who was born to him when he was one hundred and sixty-five years old, had Lamech for his son when he was one hundred and eighty-seven years of age; to whom he delivered the government, when he had retained it nine hundred and sixty-nine years. Now Lamech, when he had governed seven hundred and seventy-seven years, appointed Noah, his son, to be ruler of the people, who was born to Lamech when he was one hundred and eighty-two years old, and retained the government nine hundred and fifty years. These years collected together make up the sum before set down. But let no one inquire into the deaths of these men; for they extended their lives along together with their children and grandchildren; but let him have regard to their births only.

6:5. I will now treat of the Hebrews. The son of Phaleg, whose father Was Heber, was Ragau; whose son was Serug, to whom was born Nahor; his son was Terah, who was the father of Abraham, who accordingly was the tenth from Noah, and was born in the two hundred and ninety-second year after the deluge; for Terah begat Abram in his seventieth year. Nahor begat Haran when he was one hundred and twenty years old; Nahor was born to Serug in his hundred and thirty-second year; Ragau had Serug at one hundred and thirty; at the same age also Phaleg had Ragau; Heber begat Phaleg in his hundred and thirty-fourth year; he himself being begotten by Sala when he was a hundred and thirty years old, whom Arphaxad had for his son at the hundred and thirty-fifth year of his age. Arphaxad was the son of Shem, and born twelve years after the deluge. Now Abram had two brethren, Nahor and Haran: of these Haran left a son, Lot; as also Sarai and Milcha his daughters; and died among the Chaldeans, in a city of the Chaldeans, called Ur; and his monument is shown to this day. These married their nieces. Nabor married Milcha, and Abram married Sarai. Now Terah hating Chaldea, on account of his mourning for Ilaran, they all removed to Haran of Mesopotamia, where Terah died, and was buried, when he had lived to be two hundred and five years old; for the life of man was already, by degrees, diminished, and became shorter than before, till the birth of Moses; after whom the term of human life was one hundred and twenty years, God determining it to the length that Moses happened to live. Now Nahor had eight sons by Milcha; Uz and Buz, Kemuel, Chesed, Azau, Pheldas, Jadelph, and Bethuel. These were all the genuine sons of Nahor; for Teba, and Gaam, and Tachas, and Maaca, were born of Reuma his concubine: but Bethuel had a daughter, Rebecca, and a son, Laban.

when Adam was in his two hundred and thirtieth year,		230
Seth begat Enos in his two hundred and fifth year;		205, 435
whom he had in his hundred and ninetieth year.		190, 625
Malaleel, who was born in his hundred and seventieth year.		170, 795
Jared, whom he begat when he was in his hundred and sixty-fifth year.		165, 960
Enoch succeeded him, who was born when his father was one hundred and sixty-two years old.		162, 1122
the son of Enoch, who was born to him when he was one hundred and sixty-five years old,		165, 1287
had Lamech for his son when he was one hundred and eighty-seven years of age;		187, 1474
Noah, was born to Lamech when he was one hundred and eighty-two years old,		182, 1656 (!)

1656 Birth of Noah after Creation
0600 Age of Noah at Flood
2256 Flood after Creation

Abraham, who accordingly was the tenth from Noah, and was born in the two hundred and ninety-second year after the deluge;

2256
0292 Abraham after Flood
2548 Abraham after Creation

for Terah begat Abram in his seventieth year.		70
Nahor begat Haran when he was one hundred and twenty years old;		120, 190
Nahor was born to Serug in his hundred and thirty-second year;		132, 322
Ragau had Serug at one hundred and thirty;		130, 452
at the same age also Phaleg had Ragau;		130, 582
Heber begat Phaleg in his hundred and thirty-fourth year;		134, 716
he himself being begotten by Sala when he was a hundred and thirty years old,		130, 846
whom Arphaxad had for his son at the hundred and thirty-fifth year of his age.		135, 981
Arphaxad was the son of Shem, and born twelve years after the deluge.		12, 993

2256
0993 Abraham after Flood
3249 Abraham after Creation

So, the two informations, summary and detailed, given about Abraham's birth after Flood contradict each other like Masoretic on the summary and LXX on the detailed.

3249
2548
0701

There is a difference of 701 years between the two informations. Note that a summary one is not found in the Bible text, either for Flood or for Abraham after Flood, but the detailed one is found in the Bible text : this means that when Josephus as a very young Jew was learning Genesis by heart, he was learning LXX chronology.

And, since he is giving a summary in conflict with this, it seems he had been told this new sum of overlapping lifespans from the Synagogue, which sometimes was in conflict with him.

Anno Mundi for Exodus, Birth of Abraham, and Anno Diluvii for Birth of Abraham in St Jerome's chronology:

5199 5199 2957
1470 2015 2015
3729 3184 0942

So, the 942 years from Flood to Abraham in St Jerome's chronology (which Roman Catholics use at Christmas, if of Latin rite and not in misplaced obedience to a pseudo-Papal measure from 1994 using a newer and imprecise one), are fairly close to Josephus' detailed, but not at all to his summary chronology from Flood to Abraham's birth.

When in Contra Apionem he says that from Creation to Moses there were just a little less than 3000 years, he is of course using the summary chronology he seems to have learned as an adult.

It is a bit funny that I skim through Book I and don't find Melchisedec in it.

Hans Georg Lundahl
Nanterre UL
St Wenceslas, Duke and Martyr
28.IX.2017