I dunno about all that, CoK. I work in Afghanistan and I'm surrounded by people who are skilled at executing an operational plan but utterly drown in the realm of office politics. In war you know clearly, for the most part, who are your enemies and who is fighting on "your side". With politics, you can never be sure. And since the stakes are usually exchanges of power rather than life or death, it's easier for people like Littlefinger to move between the two.
Ned fought side by side with men who could have stabbed him in the back at any moment. He was a rebel, and not in a much different position than Rob. Rob was stabbed in the back by the Boltons, and the Freys. He completely lost the loyalty of the Karstarks. It doesn't make much difference that Rob betrayed the trust of the Freys first, the result is that Rob did not know who all his enemies were. Rob couldn't even trust Edmure, his own uncle, to follow orders in a critical situation. Rob had a lot of great victories, but they all would have paled next to the prospect of leading Tywin's army into a trap. Because Edmure failed to follow orders, Tywin failed to take Rob's bait. It was Rob's fault for giving Edmure a command, and it cost him greatly. Taking Tywin out of the picture would have been second to ending the conflict with the Lannisters.
I personally have a strong feeling that Rob was warging in and out of Grey Wind in order to gain tactical advantages over Tywin. Because Rob was never a POV character, we will probably never know whether he was, or was not. We can be pretty sure that Eddard was not warging into an animal in order to gain advantage over his enemies. In many ways, Ned handled war altogether different from Rob, whether he was warging or not. The fact that he and his army was 1. there to save Robert from Randall Tarly, when Robert needed him 2. there to save Stannis and Storms End from Mace Tyrell when Stannis needed him, and 3. was able to take King's Landing to virtually end the war, can't be ignored. As a rebel, Eddard was treading dangerous water by trusting any man very far, and yet, he was able to move about Westeros with a sizable army in a way that allowed him to be exactly where he needed to be in order to divert disaster time and time again, and eventually end the war. Leading a campaign like that would be sheer brilliance by anyone's standards. Such a leader would have to be a great judge of character under any circumstances, politically, or martially. In King's Landing, Ned was totally different, trusting the word of any man who would give it out to him for free.
You really can't even blame Ned's death on the politics of King's Landing. Certainly you can to an extent, but really....they intended for him to take the black, until that little s*** Joffrey fouled up the plan. In fact, Joffrey is more responsible for the war than Ned is, since he's the one who sent a henchman after Bran in the end.
Thank god his reign as king was short lived....just look at all the problems he caused before he ever wore the damn crown.
Whether the politics killed him or not, does not negate the deaths of the people who came south with him, and the danger that his decisions imposed upon his children. Besides, the politics of King's Landing is what allowed Joffrey to take the throne. Both Ned's politics, and the politics of everyone else involved. Ned had his chance to stop that from happening. He didn't have the best circumstances to work with, but who gets to work under the best circumstances? Circei didn't have the best circumstances either, but it likely wasn't hard for her to totally dismantle Ned's attempt to decide who should sit on the iron throne. It all comes down to who he was willing to trust while he was in power, and who he was forced to trust, because, while he was in King's Landing to rule the realm, Ned never once made the effort to build a power base, or even a plan to fall back on in order to save his family, and the people that worked beneath him, should things fall apart. Any ruler should know better. People who are unconcerned with rule, or command may not think this way, but in politics, and war, as well as in life in general, if you don't have any kind of back up plan, you very well could be asking for trouble.