Why do you mean 'do I realise that'? That may be your opinion, but I might have a different one.
Anyway, I actually agree that there should not be multiple Polynesian Civs. There could be one, such as Tonga, or maybe the Maori (Not Hawaii again as that would be more repetitive than is necessary) and this could be seen as representing the history of the region as a whole, as opposed to an ugly amalgamation of multiple groups into a fictional empire. Your obsession with creating such fictional empires as opposed to more sincere depictions makes me question why you even bother commenting on threads like these; it seems to me you have no interest in the history of regions such as Scandinavia and Polynesia.
The issue is if you have multiple potential civ candidates (cultures/nations/whatever) that have some commonalities
There are a few possible options
1. make no civ from that group
-pros: very cheap, and doesn't diminish the uniqueness of other civs in the game
-cons: interesting gameplay, geographic representation, roleplay opportunities from those civs is diminished
2. make a blob civ from those civs (ie European civ with Panzers, Roads to Rome, and Royal Dockyards)
-pros:cheap, and minimal impact on the uniqueness of other civs in the game, can allow some interesting gameplay from interesting traits in the region
-cons: ahistorical [depending on how much one power ever dominated the region, particularly recently] seems weird for roleplay/insulting to lump groups together with little or nothing in common
3. choose a representative civ from that area (ie Roman civ representing Europe)
-pros:cheap, and minimal impact on the uniqueness of other civs in the game, can allow some interesting gameplay from interesting traits in the region
-cons: leaves some areas out (missing gameplay/roleplay representation opportunities) opportunities
4. make a blob civ from those civs, with multiple leaders for individual civs (European civ with Trajan, Victoria, Charlemagne as leaders...with civ attributes being things common to all of them)
-pros:minimal impact on the uniqueness of other civs in the game, can allow some interesting gameplay from interesting traits in the region, with multiple representations adding even more gameplay and representation options... ahistoricalness minimized depending on degree of identification with 'the blob' by the leaders
-cons: maybe more expensive, slightly ahistorical, somewhat weird for roleplay/insulting to lump groups together with little or nothing in common
5. make a multiple civs
-pros: maximum gameplay options, representation
-cons: more expensive, uniqueness of all civs impacted, Especially if the civs are obscure
For Polynesia, we both agree that 1+5 are both bad options
1 is bad because Polynesia does have some really unique traits/culture/territory
5 is bad because the differences are too obscure (note: for unmodded game, mods for every possible permutatuion/shade of difference are good, but the unmodded game is different)
2-4 then is the issue
I generally think a blob civ that takes Civ attributes from cultures that opposed each other, (ie option 2) is generally bad, due to the a historicalness... particularly if the cultures were Never united
The distinction then is
3-Representative civ
or
4-Group civ with multiple leaders
I think the best is the Group civ.... even if they only make 1 leader, so that the possibility of other leaders arises. for representation.
So you could make a Hawaii civ with
-things unique to Hawaii
OR
a Polynesia civ with
-civ attributes that are Common to Polynesia
-a Leader from a particular civ (say Hawaii) with some attributes that are at least somewhat unique to Hawaii
The Advantage of the Polynesia option (if done right) is that you could add a Maori/Tongan/Samoan leader and feel like you are playing Maori/Tonga/Samoa civ...keep the civ traits to the "common traits" and keep the leader ones to the individual group ones.
.................
Note; while the traits a civ has should be unique, they can be unique even if their traits overlap (for roleplay/geography)... the problem is every single civ (especially with 4 unique categories) starts to get less unique and less recognizable (and thus less interesting) as you add more. [different people will tolerate this at different amounts, hence mods being a good idea]
But that gives my idea of a Polynesia (or title it based on the leader if desired, but that ruins the impact of playing it as another civ or as a different modded leader)
Civ Traits
-UU: naval unit available from beginning, can settle coast lines for cheap
-UA: ocean embarking from beginning, can "see" terrain (not revealing fog of war) out 5 spaces, +food to water tiles
-UI: Bonus resort
Leader U- depends on the leader..multiple options available