Right; that's what I'm talking about too. They can have that many unique planets in principle which (due to lazy evaluation, you could say) they only need to 'assemble' a small number of them. But they can all be unique. I agree with you that it's a problem of how to make them seem sufficiently different to each other though.
If you are a computer then they are in-fact unique, since every hash has a different value. But that in not what is the definition of unique for humans. Since we are humans talking in English, then we have to agree on some definitions:
Unique - 1.
existing as the only one or as the sole example; single; solitary in type or characteristics:
a unique copy of an ancient manuscript.
2.
having no like or equal; unparalleled; incomparable:
Bach was unique in his handling of counterpoint.
3.
limited in occurrence to a given class, situation, or area:
a species unique to Australia.
4.
limited to a single outcome or result; without alternative possibilities:
Certain types of problems have unique solutions.
5.
not typical; unusual:
She has a very unique smile.
By those definitions, their planets are not unique. If your definition of unique differs from those established by the language we are using, then you have to specify this.
I think both senses of unique are used in common parlance... for example, when people say "every snowflake is unique". Sure, they are similar... but not exactly the same, hence unique.
Your comment has made me realize just how easy it is for people to misunderstand each other, due to attaching different meanings to words. Of course "unique" means "distinctive" to most people. I had just managed to completely forget about it, and assumed that everyone shared the computer science meaning of "unique".
I wonder how many arguments ultimately boil down to this kind of misunderstandings over words. And it doesn't help that marketers will happily use loaded words like "unique" to create hype.