Just saw a history program called greatest tombs in history about Greek craftsmen instructing the Chinese to make the terracotta warriors and bronze statues (it's got bad qualities of being patronising, doing re-enactments of researching, ignoring the steppe route existed with Chinese/Greek goods traded both via the Scythians but still being interesting enough to watch)
This was made 2016 and there been conflicting reports of research being pulled for national prestige being hurt in China. Has there been more work presented to make this more clear?
There's a number of works that discuss the possibility of Greek (specifically Greco-Bactrian / Hellenistic) influence on the Qin Empire's art forms. I'll summarize some of the pro-Greek influence arguments here (see the sources below).
Key to the argument is that Qin, as a state located at the extreme West of the Zhou cultural sphere, could and would have had extensive trading relations with other polities on its boundaries. The terracotta statues appear to mark a historical rupture in Chinese art; their life-size scale, fine features, and naturalism largely do not resemble humanoid statues prior to their manufacture. Indeed, even after the Qin, the Han Dynasty figurines do not approach the same scale or naturalistic style of the warriors.
Lukas Nickel argues that their uniqueness may be attributed to possible contacts with Hellenistic states and knowledge of Greco-Bactrian art forms. Nickel argues that “interest in the anatomic qualities of the human body” (423) is a uniquely Greek development, and the liveliness of the terracotta statues may have even entailed direct Greek participation in their making. He also links this with the 12 metal (bronze) statues of the Qin palace, arguing that their manufacture and scale may have been influenced by the Greeks. Specifically, Nickel cites a third-century CE text that notes the appearance of giants daren in Lintao, a city that was Qin's westernmost point. Their appearance on the borderlands of the Qin may indicate reports of large humanoid sculptures coming through the West (Nickel suggests that they were modeled after the twelve Olympian gods). Furthermore, the statues are usually noted as being attired in foreign clothing.
Dr. Duan Qingbo of the Shaanxi Institute of Archaeology is also a proponent of this line of thinking - especially because the "acrobatic" figures from pit K9901 (images from the web, but are also depicted in the works below) are extremely naturalistic, with detailed musculature. There are no statues in China prior to the Qin with this level of anatomical dynamism.
There are of course people who argue that naturalism could have developed in China without external influence, I think but at least in Western sinology the presence of possible Hellenistic influence is not regarded as being particularly outlandish any more. It is still an ongoing debate, however, since there isn't any direct evidence demonstrating contact just yet. Dr Duan notes that DNA tests have been done on some of the artisans' bones near the mausoleum but they have come back inconclusive.