It's comparing apples with oranges.
For a start we already had a level of virus in the community after returns from ski resorts and so we were at a different starting point.
We could have done more with our boarders. For a start we have huge hotel chains at our airports and could have used it for quarantine. I personally think less people would have travelled because they can if the restrictions were tighter.
So yes, I agree with the fact we could have done more. But I don't think we could follow NZ and what they did as we are different and had a different starting point.