Well, I have only seen you go defensive in all these arguments but anyways..
NZ drew one series vs Aus in 1989 in which they were on verge of defeat after getting followed on. The other series was the only one where they managed to make a comeback after a crushing defeat in first test. Their overall record tells us that they were the 7th ranked team in the world in 90s and behind India and England throughout Waqar career. NZ were strong only during Hadlee era and now in Williamson era.
Btw, Waqar and Wasim both toured WI twice in their careers in 1992-93 and 1999-00 and Waqar did well in first tour but failed in second. Wasim did well in second tour but failed in first one. Result was same though- neither helped Pakistan to win a test match there. WI won 2-0 in 1992-93 and then WI won 1-0 in 1999-00. So, again they didn’t do anything special- did well in one tour but failed in the other one.
Overall result- they were inconsistent throughout their career away from home. Doing well in one series and failing in the other. The one key difference is that Wasim did well in Australia and India while Waqar didn’t.