Ficus show lots of natural variations when grown from seed. Leaf shape, leaf size, bark color, vigor etc. can vary greatly from one seedling to the next. This can even occur with seed harvested from the same mother tree.
Here is one of many Ficus virens that I have grown from seed. This individual has a rounder leaf than the normal virens. Its other characteristics are pretty typical for Ficus virens but if one were to just use the leaf shape as a major factor in the identification it might just lead you astray. This is one of the most frustrating features of Ficus, their variability. While making our lives miserable by confusing our identification it is a useful trait for the species as it enables them to modify themselves and perhaps find an environmental niche to exploit.