I think you guys are overthinking this. I dunno if its just Stead but the impression I get as an overseas guy and a fan of another team, is he is a guy who can get his side squeeze any little advantage they get and mostly use any slip ups by the opposition but when you need to make the great play to win a game, is often found lacking. Ruthless and efficient, but not quite mindblowing.
I dont know enough of the NZ domestic scene to relatively compare the talents coming through in the various eras but if you guys think this era has been your strongest and greatest then definitely I would say he has underachieved inspite of the significant achievements. For all the nice words I can think and say for you guys, everyone knows the WTC win is as much down to scheduling luck as anything else. The two finals you lost were both games you should have perhaps won. The test series wins against Pak in UAE and Ind in Ind are definitely amazing but again, it seems to me both had a lots to do with taking advantage of a slipping up opponent than a KO blow delivered by this side.
Conversely though, if you did find a coach who will take your team in that direction, you will have to prepare to lose games you would not have thought you would lose in Stead's era. But yeah, if the talent coming through is really that good, then defiinitely another coach who is willing to treat them as a team of match-winners maybe the way to go in the future, for all of Stead's achievements as of now. Every coach and management have their sell-by dates, even the best of them.