Postecoglou has shown a preference for strikers who are mobile and agile, and who can link up with the midfielders and create chances. This suggests that he would prefer a striker more like Jonathan David than Dusan Vlahovic.
For example, at Celtic, Postecoglou's preferred striker was Kyogo Furuhashi. Furuhashi is a mobile and agile striker who is good at running in behind defenders and creating chances. He is also a good dribbler and passer, which allows him to fit into Postecoglou's system.
Of course, Postecoglou is not opposed to having a more powerful and clinical striker in his team. For example, at Yokohama F. Marinos, Postecoglou's preferred striker was Carlos Eduardo. Eduardo is a powerful and clinical striker who is good at scoring goals in the box. However, he is not as mobile as Furuhashi, and he does not have the same creativity.
Ultimately, the type of striker that Postecoglou prefers will depend on the specific needs of his team. However, he has shown a preference for strikers who are mobile and agile, and who can link up with the midfielders and create chances.