For example, only a person who was actually present with Nanak could have written that starting from Sultanpur Nanak went to Delhi via Lahore (which is otherwise on the opposite side of Delhi), of course if it actually happened that way, but not the one who was not present. For then, lacking surety of an eyewitness the latter will be afraid that people will ask him that if Nanak was to go to Delhi why he should first go to Lahore or why should he go via Lahore, why not directly via this and that?
Nanak could really have gone via Lahore because Nanak was actually to go, to reach, nowhere; he was just to flow with the flow, he was just to go where things at the very moment would fall-into-place on their own to take him.
A proposal will come and he will, without thinking of anything, of destination, of distance, of route, of time would just spontaneously say either yes or no and that will be all. Again, as I said before, it is not easy to understand the ways of those who are there yet not there, doer yet not doer, who feel that things happen through them rather than by them. Completely in the now they are just in the hands of the higher power or higher reason or intuition to go wherever it will take them, they just feel like standing in the center of things as witnesses.
And it is not necessary that it was Bhai Bala who wrote that Bhagat Kabir and Baba Hundal were superior to Baba Nanak, it could have been superimposed on his Sakhi by someone else later on. In fact many things could have been superimposed later on but that does not mean that the main writing was not done by Bhai Bala not to mention that he did not even exist.
I may also add here that the talk of Kabir's or Baba Hundal's superiority would not have affected Nanak in the same way as it has affected us ego-logical lesser mortals, and if there was even a hint by somebody of the same in Nanak's presence I would not be surprised if Nanak would not have rather affirmed the same than get annoyed, in which case, Bala would be left in a preplexing state whether to go by Nanak's word or not. Who knows what actually happened or under what circumstances Bhai Bala wrote the above if at all? What needs to be done on our part is to not to be affected either way and showing humility as Nanak himself would have ordained remain sure of Baba Nanak's highest attainment ourselves. In the timeless and spaceless realm of the One there is no higher and no lower, no inferior and no superior. And Nanak of all would know it.
Bhai Kanhaiya, a Sikh, is famous in Sikh history as the person who offered water to wounded Muslim soldiers in the same way he offered to Sikh soldiers in a battle between Muslims and Sikhs at the times of Guru Gobind Singh. None would have believed if people had not actually seen him doing so. And even those who actually saw it thought it better to lodge a complaint with the Guru than appreciate him. It was only Guru himself who could understand and appreciate such a gesture of confirming that all are made by the same One God and none is your enemy once he is not in a position to fight in a battle field. Now only an eyewitness with the added help of Guru's gesture could have done justice to this episode of Bhai Kanhaiya while to others it may have looked cooked up for some ulterior motive of the writer.
As for Bala's writing that Nanak flew from one place to an other or just closed his eyes at one place and appeared at an other intended place, I will provide my own kind of logic in my next post at the same time showing that this apparent miracle too is not devoid of all reason or substance.