No, there are 2 good Portuguese managers known when they work abroad, if we take Mourinho out of the equation, I would say Paulo Fonseca or Leonardo Jardim are good prospects, a tier bellow we have Nuno Espirito Santo, Jorge Jesus, Sergio Conceição or others, unless you are trying to say to me in Portugal there is only Mourinho, wich is false.
Even from Germany I would say Marco Rose is very interesting, and they have others, its false they are garbage.
In Italy you have a full list to choose, Argentina also interesting nation to watch regarding that, I even think portuguese managers are more used to work under low budgets than the French or British, unless your name is José Mourinho in 2018, where if you don't win just throw more millions to solve the puzzle.
Oh and 2016 has nothing to do with Portuguese managers, Santos doesn't manage a club since 2010, out of question.