Originally posted by: FlauntPessimism
Even if Shakuni's son and Karna's sons and the others he killed had survived nothing would have changed in the epic.
Now during the war people fight win or lose that doesn't make any changes at all. Nakul having been a good fighter doesn't make him an important character, Lakshman was a great warrior, he killed Shikhandi's son, was the one who challenged Abhimanyu at a time when topmost Kauravas including Dron and Ashwathama were reluctant to face him, and fought bravely with him. Karna's son Vrishsen was a nightmare to Pandavas army, he had defeated all the 5 Uppandavas in a one to five combat on the very day he entered the war, single handedly nearly killed Drupad while entering into enemy arena, and when Drupad's charioteer took him away out of battlefield, Vrishsen killed half akshauni of Drupad army on his own. But that doesn't make Lakshman or Vrishsen important for the epic.
Chitrangad ji was everything that Bheeshm was, powerful, warrior, zealous, ambitious, righteous etc. but that doesn't make him important for the epic.
Same is the case with Nakul.
Nothing would have changed if these characters were not in epic.
I didn't say that everything could be written by Vyas(although if he was such a fast horse runner that is important much more important than him being handsome so should have been mentioned by Vyas), I said that riding in rain without getting wet is physically not possible.
Regarding the last part, it's not a myth, Shanti Parva is very clear that Sahdev openly supported Draupadi's demand for war.
Later in the same Parva Krishna tells Vidur that the villages were chosen by Sahdev since he knew that Duryodhan would never agree to give them.
Sahdev being a great astrologer is not of much use to the epic, but the above acts are, which is the reason he is much important unlike Nakul