Tywin as a battle commander

[The Sleeper]

You do realise that most of the fear was before Renly crowned himself and was considered to be a likely supporter of Stannis right?

What I did realize is that nearly everybody knew that Renly and Stannis despised each other and that every Lannister considered Stannis to be the real threat even after Renly was on his way to King's Landing with 80000 troops. Besides as far as they knew Renly crowned himself first. They first knew of Stannis making a claim after he sent that letter procliaming Joffrey a bastard.

[Ragnorak]

You do realise that most of the fear was before Renly crowned himself and was considered to be a likely supporter of Stannis right?

You got me wondering so I looked...

Tywin says this before anyone knows of a rift between Renly and Stannis:

His father frowned. “I have felt from the beginning that Stannis was a greater danger than all the others combined. Yet he does nothing. Oh, Varys hears his whispers. Stannis is building ships, Stannis is hiring sellswords, Stannis is bringing a shadowbinder from Asshai. What does it mean? Is any of it true?”

But Tyrion says this after the Stannis letter tips him off that Renly and Stannis both declared themselves Kings:

In truth, Renly Baratheon did not frighten Tyrion half so much as his brother Stannis did. Renly was beloved of the commons, but he had never before led men in war. Stannis was otherwise: hard, cold, inexorable. if only they had some way of knowing what was happening on Dragonstone… but not one of the fisherfolk he had paid to spy out the island had ever returned, and even the informers the eunuch claimed to have placed in Stannis’s household had been ominously silent. The striped hulls of Lysene war galleys had been seen offshore, though, and Varys had reports from Myr of sellsail captains taking service with Dragonstone. If Stannis attacks by sea while his brother Renly storms the gates, they’ll soon be mounting Joffrey’s head on a spike. Worse, mine will be beside him. A depressing thought. He ought to make plans to get Shae safely out of the city, should the worst seem likely.

[E-Ro]

I, stand corrected.

[Castel]

In truth, Renly Baratheon did not frighten Tyrion half so much as his brother Stannis did. Renly was beloved of the commons, but he had never before led men in war. Stannis was otherwise: hard, cold, inexorable. if only they had some way of knowing what was happening on Dragonstone… but not one of the fisherfolk he had paid to spy out the island had ever returned, and even the informers the eunuch claimed to have placed in Stannis’s household had been ominously silent. The striped hulls of Lysene war galleys had been seen offshore, though, and Varys had reports from Myr of sellsail captains taking service with Dragonstone. If Stannis attacks by sea while his brother Renly storms the gates, they’ll soon be mounting Joffrey’s head on a spike. Worse, mine will be beside him. A depressing thought. He ought to make plans to get Shae safely out of the city, should the worst seem likely.

This seems like the opposite of Tyrion finding out that they weren't working together.

But to add: Stannis is a proven military commander, Renly is not.Stannis is notoriously unmerciful, Renly is not. Add this to the fact that the whole political structure of the Stormlands seems obscured to Tyrion (he probably didn't know that everyone would declare for Renly, hell that was really lucky, if Renly hadn't preempted Stannis who knows what might have happened.) and you have your answer.

[Castel]

I, stand corrected.

Awww, we were just starting to get along :)