I am not sure about that. The PVA and US did not have a strong understanding of each other’s skills. Plus, the Nationalists couldn’t produce their own weapons, so their tactics were much different from that of the US. The PVA generals were just smart and understood warfare very very well, so they turned their disadvantages into advantages. For example, mountains are typically significant obstacles to any army; however PVA generals turned them into advantages. If they had maybe half of the firepower and mobility the US had, South Korea would probably not exist or at the very least be much smaller than it is now.Hi LawLeadsToPeace,
Another factor is that most of the PVA were former Nationalist soldier themselves, train by the US, so maybe they know the tactics combined with PLA leadership may had contribute to their early success.