Perhaps I spoke too strongly. Bear in mind I have consistently said Dany is in the best position of anyone to defeat the Night King and Cersei, so I understand the position she is in.
That said, Tyrion's strategy cost her all of the allies I mentioned and helped secure an alliance between Cersei and Euron. *DANY'S* strategy obliterated the Lannister-Tarly forces and sent Jaime scurrying back to Cersei defeated and with no morale, practically ready to sue for peace.
Dany will continue to lose more people in the North against the Night King, and potentially another dragon as well. Meanwhile Cersei is replenishing her forces with the Golden Company. If Dany keeps fighting as Tyrion advises, I'm not sure she will win the war. If she fights the war as she thinks she should, then yes, she will curbstomp everyone and take the throne.
Remember, if she had listened to Tyrion, she wouldn't have an alliance with the North now either. I know she's in the best position of anyone right now, but my point in saying it can be argued that she's losing the war is more to say that her strategy right now is not good and is costing her.
Sure, but the same can be said about the North as well. Tywin didn't have the allegiance of the Houses of the North, but he had the allegiance of the Warden. He may not have all of the Riverlands stepping over themselves to swear allegiance, but he no longer has armies rebelling against the crown. I don't think Tywin thought for a moment that all the Houses were now loyal to Lannister and Bolton and Frey, but I do think he thought the war was over and no one would be marching against the crown and its allies.Tywin, acting in his capacity as Hand of the King, gave Walder Frey overlordship of the Riverlands as part of his reward for the Red Wedding, displacing House Tully and several other more powerful houses (including, ostensibly, Littlefinger, who as Lord of Harrenhall controlled the largest fief in the region). The Freys ought to have been able to call on the support of all the other Riverlands houses in order to besiege Riverrun, but when they call came out, everyone else thumbed their noses at them. That's a big loss, especially as the Riverlands are one of the populous regions in Westeros. At no point in Cersei's attempts to defend Westeros from Dany did she rally any Riverlands troops and after Arya murdered all the Freys the region reverted to de-facto independence.
Yes but Littlefinger is an unforseen complication. Tywin's strategy is sound and would have worked. The North did not take it upon itself to rally together and take back Winterfell, and the Vale did not take it upon itself to go support this cause. For all intents and purposes, Tywin quelled the rebellion. When Littlefinger was sent to the Eyrie, Lysa was still alive and she had *NO* intention of moving against the Lannisters at all. Littlefinger was sent there as a reward for his service and to secure House Arryn and the Vale to not move against the crown.The Vale, like all the other sub-kingdoms, has its own feudal lords with their own holdings and troops, subject to all the same sort of loyalty issues we're currently seeing on display with the northern lords. Littlefinger had control over their nominal liege in the Arryns, but that's not enough for them to answer a call for a war they find frivolous, wasteful, or overly dangerous. However, because of the Red Wedding (and subsequent atrocities) Ramsay Bolton was incredibly unpopular and the various lords and knights of the Vale raised no objections to marching hundreds of miles north to punch him in the face. If not for the Red Wedding that would have been a really, really hard sell, especially given that most of the lords of the Vale don't actually like Littlefinger.
The Red Wedding itself is not enough to get the Vale to march on House Bolton. But it was enough to end the war. That Littlefinger is scheming doesn't take away from Tywin's strategy except for the fact that he wasn't aware of Petyr's ambitions and audacity.
The point is that Tywin stopped the war. Tywin didn't kill Renly but he doesn't have to, he has to have the know-how and acumen to use it to his advantage, which he did. He arranged a marriage between Margery and Jeoffrey, and Loras and Cersei.Tywin secured a warden in the North (Bolton) and in the Riverlands (Freys). The Tyrells joined up for their own reasons following Stannis using magic to murder Renly - which Tywin was emphatically not responsible for doing, though he did successfully exploit the situation. Tyrion, actually, is the one who secured a (temporary) peace with Dorne via a marriage alliance.
Tywin is probably *the best* player of the Game of Thrones in the entire show.