[...]
Let's disregard the Dornish political dynamics from the book. There still are noble houses as I already established, who are sworn to House Martell. Again, we don't know whom exactly takes what position, but really, there are only 3 positions they can take towards the Martells:
- They can be loyal to Doran, then they definitely would not support Ellaria.
- They can be rivaled to Doran, and might even support the Snakes. But there is no reason they would follow those bastards any further than killing off the Martells. Because why should they follow these bastards, the lover and daughters of their rival's brother?
- They can be neutral in the political situation. In that case, they wouldn't support Ellaria either way, because why should they?
Again, with bastards not being legitimate even in Dorne, unless the Snakes have a proper noble to take up the throne of Sunspear, they have absolutely no claim, and even if they should have forged alliances with Doran's rivals in order to stage the coup, at this point, not a single Dornish house should follow them.
[...]