Hong Kong's ONLY tariffs relate to tobacco, alcohol, and fuel. That though was motivated not by nationalist protectionism but rather by the desire to protect public health and the environment.
As far as I know, Singapore has no tariffs whatsoever or if it does, like in Hong Kong, it imposes them only on non-desirable products.
Feel free to prove me wrong. From all I've read, Singapore has gone to unilateral free trade:
https://policyexchange.org.uk/wp-content/uploads/2018/02/Unilateral-Free-Trade.pdf
Here's an example of a Singaporean Free Trade Agreement:
https://www.huffingtonpost.com/simon-lester/excluding-tobacco-from-tr_b_12750088.html
You'll notice that Singapore and Australia are already free traders. If anything, they were negotiating reducing free protection on tobacco companies. In other words, when a country is protectionist, it's busy negotiating for the union lobby. When it's a free-trading nation, it can shift its focus on public health, safety, and other more important matters.