These pictures of 1 WTC by @paulgomango on instagram show how 1 WTC only has the presence the north tower (if it was still standing) had:
https://www.instagram.com/p/CZmPGhcu3He/
https://www.instagram.com/p/CZo1WegOuzY/
https://www.instagram.com/p/CZg4XySOF8f/
As these images show, 3 WTC and 4 WTC look more like shorter twins, while 1 WTC stands alone. It will take the construction of 2 WTC to regain some of the heft the original twin towers had on the Lower Manhattan skyline.