As I understand it, the various Netherland options are not as ahistorical as you are implying. Gelderland and Friesen were actually independent in 1492, so that option is pretty much ok. (Although the rest of the lowlands should perhaps be in Austrian control. However, we want the Dutch to fight the Spanish, not the Austrians.)
The "Austrian Netherlands" option is also historical, since the lowlands were actually under Austrian Habsburg dominion.
The last option; Austrian/Spanish lowlands, is designed to have the Dutch revolt against the Austrians, then fight the Spanish for control of the rest of their domain.
Obviously there are more ways to combine these options, but I really don't think we need all the possible permutations.
The "Austrian Netherlands" option is also historical, since the lowlands were actually under Austrian Habsburg dominion.
The last option; Austrian/Spanish lowlands, is designed to have the Dutch revolt against the Austrians, then fight the Spanish for control of the rest of their domain.
Obviously there are more ways to combine these options, but I really don't think we need all the possible permutations.