Ralph is right, most of these Ficus were started as cuttings. In tropical countries, this is common practice.
One of the surest signs that these trees were trained as bonsai from cuttings is their "perfection" They are just too perfect for a yamadori, which usually display features normally considered "faults" that due to the ingenuity of the artist were transformed into highlight features.
However, if you want to achieve this look on your tropical bonsai, you have to move to a tropical country. Doing it in a temperate zone will take a lifetime. In Taiwan, it takes only half a lifetime.
