There is certainly ambiguity when there is no harmony of views concerning secular chronology and the exegesis of the seventy years and that is of their doing. The Society's chronology is based upon evidence both biblical and secular and harmonizes prophecy but yours is useless, a dead-end which really illustrates the typical cultish-apostate mindset.
Silly!
What ambiguity?
This is the same ploy mystics of the mind use when they tell you we can't know reality because we can't fit the objective world inside our head.
Therefore, we better just listen to their authority instead. The Catholic Church uses this to trump the Sola Scriptura approach of Protestantism.
Well, we send rockets to the moon and back by a pretty fine grasp of details. So too with chronologies based on archeology.
Secular scholars only differ on minor details and not the broader facts. They know the forest from the trees. The Watchtower is "stumped" by so much clear-cutting the use the logjam to hide behind.
Here is the game the Watchtower has always played:
1.Don't learn bible languages by going to school and getting a degree like real scholars; make up what you want to believe.
2.Fill your library with secular reference books and use them for partial quotations to color your pronouncements with a scent of learning.
3.Cherry pick quotes and pit one statement against another. Raise red flags of disharmony largely by rhetoric.
4.Lead your readers by the nose using your MAGISTERIUM of "faithful and discreet slave" whenever you are on thin ice. Make scholarship a question of--not facts--but obedience to you.
5.Stonewall and play a broken record. Instead of answering objections directly use a magician's skill of misdirection to point away from yourself.
6.Paint with a broad brush. Use fancy footwork and dazzle them with bullshit.
7.No other religion has produced as many reference books that became uncomfortably error-ridden the way the Watchtower's books have.
They mysteriously vanish only to be replaced by "new light" versions. It almost makes you feel like they are hiding their ineptitude.