On Ned, Jon, and Robert's Bloodline and Family Trees

[Rhaenys_Targaryen]

Hey Rhaenys :) you make a good point on ages. But how was Daeron's keep Dragonstone when his uncle was the Prince of Dragonstone?

Baelor died in 209AC, Aemon was done with his studies in 217AC, Maekar became King in 221AC, and Daeron, as his heir, would have become Prince of Dragonstone in 221AC as well.

Where Aemon served between 217AC and 221AC is unknown, but the books told us that after Maekar had become King, Aemon went to serve at Daerons "keep", and the app revealed (a few months ago) that Daeron's seat was Dragonstone.. Which should not be that surprising, because he was, after all, Maekaer's heir.

[King Viserys Targaryen IV]

Because Tully joined the Rebellion later, didn't really had any casus belli against Aerys, and his house is both less traditional and less powerful than most of the LPs, so he would never be taken seriously as a contender.

I don't buy that at all.

It's my belief the had Robert died at the Battle of the Trident due to his injuries at the hands of Rhaegar (after Rhaegar himself died) that Hoster Tully would have become King.

Firstly if you look at who could have replaced Robert the list is only 5 people long (and only 4 with a real chance). Hoster Tully, Ned Stark, Jon Aryn, Stannis Baratheon and Tywin Lannister.

Because the Lord Paramounts would never allow a bannerman to rise above them its a short list.

You can cross Tywin off the list immediately because he joined the Rebellion at the last possible chance and the other don't trust him. They need his gold but they dot trust him

Stannis gets crossed off because he is under siege at Storm's End and has no one to champion him to the other three Lord Paramounts. Plus add to that he is not well liked by his brothers (Ned and Jon would know this) or anyone else for that matter.

Jon Aryn would have the Ancestry and leadership to be King, but he lacks two things that hurts him... Heirs and marriage potential. He has no heir for the Iron Throne and no heir to leave the Vale to. He is also married so he can not be married to another family to bind the Kingdom together (Lannisters, Martells or Tyrells)

Ned Stark would make a good candidate, he has an Heir in the unborn child in Cat's belly and an heir to leave Winterfell to (Benjen). Although he is married because he has an heir he has the promise of a future marriage to his heir to try and create those alliances. In the end Ned doesn't want to be King and would rather go back North. Now maybe he could be talked into it, especially if he sees it as his duty but he is not going to try and seek it out.

That leaves Hoster Tully. He is a Lord Paramount. He has an Heir for the Throne (Edmure) and a heir for Riverrun (Black Fish), he can also promise Edmure to marry Cersie to bring the Lannister's power and gold in to the fold. The only thing that hurts him is his families short time as a Lord Paramount, but with the backing of the North, Riverlands, Stormlands and the Vale, plus the backing of the Westerlands due to Edmure's marriage there would be no one to say no. The Reach and Dorne were defeated and would have no say.

The Throne was taken by force and the Targaryens disposed of, so the succession rules of the Targaryen line would be ignored at that point.

So unless Ned Stark actively seeks the Throne (which is against his nature) Hoster would more than likely become the new King.