Forgetting all other issues, I am assuming you are using a PHP redirect to accomplish this and that you have three sites: .co.nz, .co.au, and .com which you are using the geo targeting preference for US.

Given that you have three sites, they will be indexed individually based on all the normal ways a site is indexed. So, links to site A will bring a googlebot. Sitemap of site B will bring same. Etc. If you are using some type of cross domain canonical or have any redirects of one site to the other for any reason, they will be followed across as well.

All domains will be crawled independent of one another. So, you need to get links to each.

Best,

Maxime,

While I agree the speed might be different with in country hosting given they are both European countries. (Not true in some others.) But the question was around content duplication.

Again, I think your intent is good. But, since he has two separate domains. ExampleSite.be and ExampleSite.nl, he has no need of hreflang="x" since both are in Dutch. If he had Dutch and English it would not matter if it were the same domain or not:
From Gianluca Fiorelli mozPost

**if Page A (US version) exists also in Page B (Spanish), C (French), and D (German) versions from other countires, no matter if they are in the same domain or different, then on page A you should suggest the last three URLs as the ones Google must show in the SERPs in their respective targeted Googles. **

Again, since they are ccTLD's and they are already geotargeted by virtue of same and since they are both in Dutch, there is no other worry re duplicate content.

I am open to being shown I am wrong as it will not be the first time

Best to you, thanks so much for your replies,

Robert

Maxime,

I have to question this as you have it. The intent is there, but you are throwing everything at a problem and some of it does not work:

1. for a ccTLD, there is no geotargeting in WMT: from GWMT:

Sites with country-coded top-level domains (such as .ie) are already associated with a geographic region, in this case Ireland. In this case, you won't be able to specify a geographic location.

2. He does not need this in a cross domain setting.

3. Given he has ccTLD's this is an unnecessary expense and will add no value.

Hope this clarifies for you,

BenVer

In a short answer, not much. This is from GWMT:

Websites that provide content for different regions and in different languages sometimes create content that is the same or similar but available on different URLs. This is generally not a problem as long as the content is for different users in different countries.

Since you are using ccTLD's, Google already knows that you are targeting that specific country. 

While this will not guarantee that the .nl doesn't outrank the .be in Belgium, it will take care of your duplicate content concerns.

IMM

My first suggestion will be that you take a step back so you can save a few steps.

You need to be clear as to what you are targeting and here is why: If, your intent is to use Spanish words on English search here in the U.S. (I am in Texas, speak Spanish, handle multi lingual sites, etc.) you need to know which terms are going to return for English, Spanish, or both. Unless you are using a term that readily goes across both languages you need to go either/or there is no Spanglish to speak of. Examples are search on ropas (see screen shot) and you will get both types of languages returns. Change the search to vendes ropas or vender ropas and it is almost all returned as Spanish. Then, search on abogado and you will see English and Spanish sites. (Dumb English speaking sites, yes).

Another question is when you say hispanics, what are you targeting? People from various Spanish, Latin American, or South American countries who now reside in the US and speak Spanish only? Those who speak Spanish and English and are from a hispanic country but living in the US? Or a specific geo target area  of hispanics within the US? Remember that the majority of hispanics in the US speak English as their primary language.

So, to do KW research, you need to get clear on what it is you are selling and to whom you are selling it. Then you can become a laser for the language.

But, I would also say you need to be clear as to how you are translating and what is needed with regard urls, etc. When you have two languages on a site, you need to make sure you handle it correctly.

Hope this helps,

Pravin,

Think about it this way: If a low ranking "carried over" none of us would ever be able to increase rankings. Especially those of us in agencies who go into large sites that cannot be rebuilt at this time. So, don't worry about that.

A couple of things are these: Redo the content and if the site has a blog, feature some aspect of that page in the blog and link back so that someone reading the blog who might not go to the page again sees it, they can go to it from the link.

Then, if you can change an image or  add to the page in some small way each month, do that.

If the other on page is good, you will likely see a rise. Yes, still do work on getting more links, etc.

Hope this saves you a bit of work.