It is easier to refute than to support this theory because external trends provide opportunities without necessarily picking a winner. Only Melaka’s rise fits the claim, and then only if we assume that the Ming picked Melaka rather than the other way around. Students can justifiably argue that its ruler took the initiative to court the Chinese (we do not know enough to decide which side made the pivotal move, so we let students argue this either way). Note that the question is not asking which set of factors is more important but whether external factors will largely decide which location (out of many) thrives.
The best answers for agreeing with the proposed theory argued that local efforts were all derived from shifting external trends, particularly the founding Rajas of Temasek and Melaka (students get to decide whether such founders are external or global since there is no objective standard available). Such answers also claim that Palembang’s military power came from profits derived from trade with Tang China. While there is so doubt about this, we are willing to let this point pass if argued well.
Good answers must cover the external and local factors for the rise of all three hubs well and come to a conclusion that actually fits the evidence offered. Quite a few of you paraded the evidence well only to formulate conclusions that either contradict your discussion or addressed a different question (e.g. can local effort explain the rise of hubs on their own).
My sample answer for “refute”
Reasonably favourable external circumstances were necessary but not always sufficient in deciding whether pre-colonial Malay hubs rose to become thriving locations. Without improvements