Brunei also has a wonderful patrol boat navy, bought by its oil wealth. Considering the nation's size, corvettes aren't needed unless a North Korea is one of her neighbors. Fortunately, Brunei's neighbors are Indonesia and Malaysia. As you noted, if Brunei had a sizeable navy of personnel, and a large city population of Singapore, I would think differently. But Brunei don't.
Since these are good corvettes, there are a number of nations which could buy them. A larger number of nations could buy them if there is a considerable discount. These corvettes would fit very well into the Brazilian navy. Like Malaysia, Brazil is attempting to build its industrial base too. But its my opinion a nation learns not by just building, you can learn as much breaking things down and putting them back together.
The worst navy in Latin America in my opinion working with obsolescent equipment is Uruaguay. These three corvettes would modernize their navy instantaneously.