Both Trent Boult and Tim Southee didn't get a game in the 2016 T20 World Cup in India, with New Zealand packing their attack with spin and preferring the hit-the-deck style of Mitchell McClenaghan. Five years later, both Boult and Southee have played crucial roles in New Zealand's progress to the semi-finals from a group that included three Asian sides - Pakistan, India and Afghanistan.
Boult is currently the joint second-highest wicket-taker in the competition with 11 wickets in five matches at an economy rate of 5.84. Southee has got four fewer wickets than Boult, but his economy of 5.70 is the best among seamers who have bowled at least 20 overs in the tournament. Williamson hailed their contributions to an attack that is without the injured Lockie Ferguson.
"Yeah, they've been brilliant," Williamson said. "They've been involved with the team in all formats over a long period of time and really experienced operators for us and experience in terms of playing in all different conditions and executing their skills beautifully and performing their roles to the highest standard. They've been doing a fantastic job for us, really leading our attack who have been performing well and adjusting well to the different surfaces we've been on and a real strength in our side."
In the 2016 T20 World Cup semi-final in Delhi, Jason Roy belted 78 off 40 balls to knock New Zealand out. He has now been ruled out of the rest of England's ongoing campaign, as has been left-arm seamer Tymal Mills, but Williamson is still wary of England's incredible depth in white-ball cricket.
"They're both big players for England," Williamson said. "It's a real shame that they have suffered injuries in this competition. But I think one of the strengths as well of the England side is their depth that they've managed to produce over a period of time. And having spent some time at the Birmingham Phoenix and being sort of a little bit involved in that 100-ball comp, you can tell that there's a huge amount of talent throughout. They're still very much a very strong side who have been playing some really good cricket.
"Whenever there's an injury, there's someone else who comes in and you're not to know who they are until the toss. But you try to prepare and plan as best you can and then when you go out there, you're sort of competing in the moment. And that's kind of all that matters then. But Jason's a big player for England and has been playing really nicely and getting the team off to good starts along with Jos [Buttler]. But, as I mentioned, the depth on the England side is one of their strengths and we'll try and plan accordingly to the best of our ability. But largely [we] want to focus on the sort of cricket we want to play as a group and keep developing on that as we've been doing throughout this tournament."
Williamson's niggly elbow had prevented him from playing for Birmingham Phoenix at the inaugural Hundred, but he did spend some time there as the side's mentor. Having watched Liam Livingstone's brutal power-hitting from close quarters at the Phoenix, Williamson identified the batting allrounder as one of the threats but backed New Zealand to find a way.
"Look, they've got match-winners throughout their team and that's been a big, I suppose, movement of their white-ball side," Williamson said. "Sort of power-packed and bat deep as well. I spent a little bit of time with Liam at the Birmingham Phoenix and he played superbly well throughout that 100-ball competition, so there are a number of threats and a number of match-winners. We also have a number of match-winners as well and at the end of the day it's about committing to what you do as a team and we both do it a little bit differently."