The Scenario: Joffrey and Tommen's Untimely Deaths

Imagine the fate of the Seven Kingdoms had Joffrey and Tommen Baratheon perished at the same time. This dramatic turn of events would have reshaped the dynamics of power in Westeros, leading to a series of complex political maneuvers and alliances.

The Iron Throne and Beyond

With Joffrey and Tommen dead, King Stannis Baratheon would rightfully claim the Iron Throne. His claim, however, is mired in controversy, as he is seen as a rebel and a traitor, and his belief in an alien god raises questions about his legitimacy.

Queen Cersei's False Hope

Despite Stannis's claim, Cersei Lannister, the power behind the throne, introduces Princess Myrcella Baratheon, who, though illegitimate, is still a Baratheon. By law, she technically has a stronger claim than Stannis, making her a formidable contender. This makes the Lannisters and the Tyrells consider making Myrcella queen, thus securing their alliance.

The Tyrell Wedlock: A Strategic Alliance

Once Myrcella ascends, the Tyrells would likely want to marry her to Ser Loras Tyrell, effectively entering her into the royal bloodline. This move would solidify the Lannister-Tyrell alliance, ensuring mutual support. Conversely, if Prince Trystane Martell were to marry Myrcella, the Tyrells would likely sever their alliance with the Lannisters due to their longstanding animosity towards Dornishmen.

A Southron Disillusionment

Even if Stannis technically becomes king, most lords in the south would likely refuse to recognize him. Recognizing Myrcella as the rightful queen would not only align with the traditional preferences of the South but also secure the support needed to stabilize the realm.

The Return to Kingslanding

The Tyrells, no longer invested in the Lannister cause, may return to Highgarden. However, they would likely stay to witness Tyrion Lannister’s trial for the murder of the King and Prince. This move could be seen as a strategic observation rather than a commitment to the Lannister side.

The Dornish Response

Given the unavailability of the Sand Snakes to act, the Dorne plotline would be erased. Doran Martell, now with an interest in peace with the Crown, would likely have sent 5,000 Dornish troops to Kingslanding to support the new regime. This move would alleviate any potential conflict and promote stability in the realm.

Consequences for the Lannisters and Their Rivals

Cersei Lannister would find herself in a precarious position, with Myrcella needing protection from Trystane Martell. Cersei would therefore find an excuse to slip him a lethal dose of poison, ensuring he remains out of Myrcella’s way. Despite her victory in the trial with Gregor Clegane as her champion, Myrcella would forever doubt her mother's actions.

The Arrival of Daenerys Targaryen

Daenerys Targaryen's arrival would further alter the political landscape. With the Lannisters under pressure, Daenerys, with Kevan and Jaime Lannister as her top advisors, would swiftly surmise that a fight for the Iron Throne is futile. Consequently, she would order the surrender, leading to the unification of Westeros under her banner, eliminating the need for a wight hunt and the fall of the Wall.

The Tyrell Proposal

Seeing that Myrcella lacks a husband, the Tyrells might offer Loras Tyrell as an alternative, hoping to secure a grandchild on the throne. However, Olenna Tyrell, fearing Cersei's power, would be wary of such an alliance.