New Zealand also are in good form and there only major ICC trophy is Champions trophy back in 2000. Like you said earlier that they are performing well in sub-continent, so we can't rule them out. South Africa are also in good form and let's see whether they break there tradition of being 'Chokers' in every ICC Event.
Pakistan preparation for ICC champions trophy are well exposed in recent tri-nation series. With players like Faheem Ahraf and Kushdil shah you can't expect a win in ICC event. Moreover main batsmen and bowler, Babar Azam and Shaheen Shah are out of form.
New Zealand and South Africa choke when it come to major ICC tournaments. On top of that, they don't have a lot of experienced players and there is a tendency to buckle under the pressure. Compared to these two countries, I would say that Pakistan has a better chance of becoming champions. They have the dome advantage (apart from matches that are being played at the Dubai International Cricket Stadium), and their recent form has been quite good. That said, the favorites to win the trophy this time are Australia and India.