Their bowlers did quite well to pick quick wickets of their openers. Smith is the biggest hurdle for them. Even if they are able to pick openers wicket , Smith will take the responsibility and we know how good he is at that ( Ashes ).
They didn't win the series yet. The 1st match was abandoned and the second one was won by AUS, so they are just in lead and have to win this match to win the series. But since 107 is the target set by Pak for AUS, I think they'll win this series easily. They are already 45 in 5 overs.
The Eng vs NZ match is a crazy one. NZ won't be able to chase down 241 runs and have already lost 9 wickets in the chase. Very poor performance by NZ bowlers and not one batsman managed 50+ runs. England completely overpowered them.
I wouldn't say that NZ performed poorly. They were just outperformed by the ENG. Even if you bowl well and get thrashed for boundaries by both Morgan and Malan for a few overs, the morale of the bowlers will automatically drop. That's what happened in the match. And for chasing such a massive total of 241 runs, you'll have to score around 12 runs per over. That's not easily achievable, you have to score consistently and look for boundaries. So the NZ batsmen had no choice but to go for big shots and eventually lost their wickets. I would say that NZ went down with a fight.