Dont forget that the principal applicant can't get a work visa/permit until they have a job offer. When we first came to NZ we didn't have enough points to apply for residency straight away, so we got a two year work permit (this was four years ago, I'm not sure you can get a two year one now!!!!) After one year we applied for residency, and got it three weeks after submitting our ITA - we could then also list NZ work experience which helped with points. When we were still in the UK discussing our options for getting here we went to an expo and asked the immigration officer that very question. "Would we be able to keep renewing our work permit until we were in a position to apply for residency?" His reply was basically that they would probably do it once and then encourage us to go for PR...... just his take on the situation
HTH