Vietnam is very tricky. In my industry, those who runs business in Vietnam cannot repatriate their earnings out. So maybe, mark-up the export prices to Vietnam and retain the profits in Singapore, but Vietnam imposes high import-duties. LPPL, the higher you declare your import prices, the more taxes that you pay.
Then vietnam customs is also very corrupted like China, they just more transparent, you pay your dues, you get your goods. Businessmen or their forwarders need to go police station's "custom desk" to submit bags of cash to get their goods release.
Lastly, those who study hard and work hard in Vietnam are the women. I also don't understand, you hire viet men, you will vomit blood. The factory workers, the good office managers, are mostly female.