Bamidbar: Why did the divsion into groups only happen a year after they left Egypt?

 Emes L’Yakov (Bamidbar  1:11) Question Why was the division into different groups only done a year after they left Egypt In addition the banners served to divide the nation into unique groups and thus undermine unity?Answer  The counting was to arrange the tribes according to their banners.  However since they now had a common center – the Tabernacle there was no longer a danger of factionalism as there would have been when they first left Egypt.  This is like a person who in spite of having specialized parts such as ears and eyes remains a single entity.