Yeah. There are just so many issues and ways for this to go wrong.Really interesting. They didn't expand on this theory as much as the rest, but having John/Aegon's Targ/Stark heir come South with a wilding army to claim the North and then further South with the Northern army and the Wildling army to take the Six Kingdoms is 100% in line with the history of Westeros as it's been written.
I should have mentioned when I posted it that I have a passing knowledge of Polish history so I immediately thought on Sunday night that electing a king with family ties to the most powerful house outside the kingdom was never going to end well. I'm happy to see someone with much more knowledge than I do write it up.