A bunch of proposed flags for Finland. I am personally partial to 4, 5, and 17.
I think these are the best official proposals in this thread, but some of them are already taken. I like 13 and 1.
The NZ flag having some similarities to a handful of national flags (also territories and sometimes yacht clubs depending on how hard someone is grafting to make their point) has never struck me as a very compelling argument for change when near half the world’s flags are a variation of a triband and in which Liberia, America and Malaysia coexists.
Not to mention Romania and Chad, and Monaco, Indonesia and Poland.
And I never really understood this counterpoint, since the fact that something has happened before does not, in and of itself, justify it. Sure, there are precedents of flags being generic and easily confused for each other... which makes that less of a bad thing? On this site we often make fun of the US state flags with complex seals on blue fields and I have never heard of anyone trying to justify them just by pointing out, "well there are others, aren't there?", which I hope you agree would be a strange way to defend them.
I think precedents are only useful insofar as their observed consequences. I would say that these examples are not confused as often as the case of Australia and New Zealand anyway. The tribands have significant differences in colour and orientation. Liberia, the United States and Malaysia are also visibly distinct in their cantons even for an uninformed observer. The cases of Romania and Chad and Monaco and Indonesia are closer in design but rarely do we find contexts in which we encounter both countries at once. Australia and New Zealand do find themselves at the same contexts and the countries themselves are sometimes confused, so in practice we find their flags mixed up even at very official or professional levels.
Proponents of flag change cite the precedents of Canada and South Africa because the consequences (iconic, memorable and resonant flag designs) were positive, not just because it happened.
Liechtenstein once found out that they had an identical flag to Haiti at the Olympics and adjusted their flag accordingly. They seem to think the way that I do.