Should Australia and New Zealand be combined in one trip?
You can combine them, but do not treat them as nearby chapters. Australia and New Zealand both reward space, and a short trip split between them can become a long-haul sampler with too many airport days.
Answer
The combination can make sense when the trip is long enough, flights line up cleanly and the goal is a broad taste rather than depth. It is weaker when ten or fourteen days are split across countries that each deserve route discipline. Australia’s scale and New Zealand’s road-trip rhythm both punish casual add-ons. A better short trip is often one country done well; a better long trip is two edited routes joined by a sensible flight, not a heroic map across both.