Already did. 

I start from the premise that, if Varys could save Aegon, he would – for the same reasons that he attempted (but failed) to save Ned Stark and attempted (and succeeded) to save Gendry. 

Then the question is, what would Varys do with such a child? Well, from his dialogue with Kevan, Varys strongly emphasizes nurture over nature, that the problem with the Targaryens (although the analysis easily extends itself to Joffrey et al.) is that they are raised believing that rulership is their birthright, rather than their duty. Hence the idea that the monarchy could be perfected, and through it Westeros, if the education of the monarch is reformed. 

But as to why Varys might care about the second swap, I think it would be A. that someone he trusted betrayed him, and B. it would have involved the death of a child he would have gone some lengths to save. 

I think he was in deep denial. 

Probably. 

The Blackwoods are the only highborn house that we know of, there could be more and there could be smallfolk who follow the Old Gods no matter what their lords say. 

As for the Tullys and Vances, they likely had other motives. The Vances had warred against House Teague for the crown of the Riverlands in the past, and the Tullys were vassals of the Vances. 

I doubt things would have changed much. Why would anyone in the Riverlands trust them, after 300 years of occupation?

turtle-paced:

No, because in that field, Ramsay’s army isn’t static. It’s part of the movement of men and horses going on. 

Think path of least resistance – on an open field, it is easier and safer for the combatants, regardless of the side they’re fighting for, to step around prone bodies (which may or may not be dead and definitely have pointy metal on them) than to climb over same. Where the fighting’s over a chokepoint, it’s easier to climb over the corpses than to go around.

The battle for Winterfell took place on reasonably flat and open ground, plenty of space for both sides to move. Those corpse piles looked as though someone had raked them up like dead leaves.

Amen!

Seriously, giant walls of bodies are a phenomenon of war that you can find in many places and many times, but they happen in very specific circumstances: a breach in walled defenses through which a Forlorn Hope has to attack or a particular location in trenchworks where the spearpoint of an assault gets bogged down (they were quite common during Grant’s Overland campaign during the American Civil War, for example). 

If they had wanted that phenomenon in Episode 6×09, it would have made way more sense as part of the storming of Winterfell than out in the open fields. 

It certainly didn’t help Slynt, probably helped stall him short of a majority. 

See here or here. 

1. It’s magic, although magic can be used as trickery (Melisandre’s bit with the leeches, for example, is using clairvoyance to pretend that she can cause people’s deaths through blood magic).
2. We know from Melisandre’s POV chapter in ADWD that her ability to see and understand the future in the flames is sharper the closer things are to her own person. 
3. From a Doylist perspective, why go to the effort of writing out a whole Davos chapter in which Melisandre explains she needs Davos’ boat to get inside the magical protections of Storm’s End, if the magic had nothing to do with ti?